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1
Ballet, Jérôme. "Contribution à l'élaboration de composants électroniques organiques à base de poly(3-octylthiophène)." Phd thesis, Université Paul Sabatier - Toulouse III, 2006. http://tel.archives-ouvertes.fr/tel-00131179.
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Le travail présenté dans ce manuscrit concerne l'étude et la réalisation de diodes et de transistors à couches actives polymères. Le polymère utilisé pour cette étude est un poly(3-octylthiophène) régio-régulier synthétisé par M. Delabouglise du Laboratoire d'électrochimie et de physico-chimie des matériaux et des interfaces (LEPMI). Cette étude constitue le premier travail dans le domaine de l'électronique organique au sein du LAAS. Le premier chapitre constitue une revue assez exhaustive des travaux de la littérature dans le domaine. Nous avons notamment détaillé les principes de conduction dans les matériaux organiques en rappelant l'importance des orbitales moléculaires dans le déplacement des charges. Cet état de l'art a aussi consisté à faire un inventaire des principaux matériaux organiques référencés dans la littérature et de comparer leurs performances.
La suite du manuscrit fait état de technologie de mise en œuvre et la caractérisation des diodes à base de P3OT. Le 2ème chapitre décrit donc les différentes étapes technologiques permettant d'aboutir aux diodes. Elles sont basées sur le principe d'une mono-couche de P3OT prise en sandwich entre une anode en ITO et une cathode métallique. Nous avons identifié à partir des caractéristiques électriques des diodes réalisées les modèles les plus adaptés à la description de leur comportement. Une étude capacitive a notamment permit de révéler la présence d'une charge d'espace à l'interface métal/polymère.
Le 3ème chapitre aborde la réalisation de transistors de type TFT à base de P3OT. Nous avons extrait de la caractérisation de ces composants une mobilité par effet de champ de 4,1.10-5 cm².V-1.s-1. Nous avons, aussi, mis en exergue l'augmentation de la mobilité en fonction de la tension de grille. La présence importante de pièges à l'interface SiO2/P3OT ou dans le volume du matériau a été mise en évidence. Le vieillissement de nos transistors a aussi été abordé, notamment lors de leur exposition à l'oxygène.
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Hamidi, Sakr Amer. "Thin films of polythiophenes oriented by epitaxy and high-temperature rubbing : correlations with optical, charge-transport and thermoelectrical properties." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE019.
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Le but de cette thèse est d'étudier l'effet de l’alignement et le contrôle de la morphologie de films minces de polythiophènes et de les corréler avec les propriétés optiques, de transport de charges et thermoélectriques. Puisque les polymères semiconducteurs sont intrinsèquement anisotropes, il est essentiel de les aligner afin de comprendre leur propriétés. Cette étude a été réalisée en employant deux techniques qui ont permises d’obtenir des films minces orientés. Le brossage à haute température et la cristallisation épitaxiale directionnelle (CED) ont conduit à des films de polythiophène hautement orientés avec des paramètres d'ordre allant jusqu'à 0.87 et des taux de crystallinité jusqu'à 65%. La technique de brossage nous a permis de contrôler avec précision les tailles des domaines cristallins dans des films de P3HT brossés. Par cette méthode, nous avons pu également déterminer les températures de fusion à l'équilibre de différents poly(3-alkyl-thiophène). Nous avons appris que la largeur de bande du couplage excitonique W dépend des dimensions des cristaux dans les films minces brossés. Cette étude à aussi montrer l’importance de la planarité des chaînes pontant les domaines cristallins à travers les zones amorphes sur les propriétés de transport de charges. Nous avons également mis en évidence la morphologie particulière du poly (3-butylthiophène) (P3BT) et le rôle des groupements butyles. La méthode de cristallisation epitaxialle a été utilisée pour orienter des films de poly(3-dioctylphenyl-thiophène) (PDOPT). Nous avons examiné l'effet de la masse moléculaire du PDOPT sur le degré de cristallinité et l'alignement. Ceci nous a permis de proposer un modèle structural montrant l’absence de pi-stacking dans ce polythiophène. Finalement, nous proposons une méthode en deux étapes d’élaboration de films minces conducteurs alignés. Le brossage des films puis le dopage des polymères semiconducteurs de type-P a permis d’obtenir des propriétés thermoélectriques anisotropes améliorées.Cette thèse démontre l'importance du contrôle de la morphologie et de l'alignement des polymères semiconducteurs et conducteurs pour comprendre leurs propriétés fortement anisotropesThe aim of this thesis is to study the effect of alignment and morphological control on polythiophene thin films and to correlate this control with the optical, charge transport and thermoelectric properties. Since semiconducting polymers are inherently anisotropic by nature, studying these polymers in the aligned state was essential to understand their properties. This study could be achieved by employing two techniques that are successful in orienting polymers in thin films. High-temperature rubbing (HTR) along with directional epitaxial crystallization (DEC) produced highly oriented polythiophene thin films with order parameters reaching 0.87 and crystallinities up to 65%. HTR was a successful method to control crystal sizes in rubbed poly(3-hexyl-thiophene) P3HT films. By this method, the equilibrium melting temperatures of other poly(3-alkyl-thiophene) P3ATs were calculated. We learned that the free excitonic bandwidth depends on the crystal dimensions in the rubbed thin films. We also learned that the planarity of tie-chains linking consecutive crystalline domains plays a very important role in field-effect mobility. We also discuss the peculiar morphology of poly(3-butyl-thiophene) (P3BT) and the role of the butyl side groups. Then DEC method was proposed to orient poly(3-dioctylphenyl-thiophene) (PDOPT) thin films. We examined the effect of molecular weight of PDOPT on the level of crystallinity and alignment. Consequently, this relation provided fundamental information that helped us refine the crystal structure of PDOPT. Finally, a versatile method to produce highly aligned conducting polymers was proposed. HTR followed by P-type doping proved to be an excellent way to produce highly aligned conducting thin films with enhanced thermoelectric properties. This thesis brings value to the importance of morphology control and the alignment of semiconducting thin films to understand the various properties of these highly anisotropic systems
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Duarte, Daniel André Pires. "Otimização de células solares orgânicas do tipo P3HT." Master's thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/11349.
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Mestrado em Engenharia FísicaNo presente trabalho procedeu-se ao fabrico, caracterização e otimização de dispositivos fotovoltaicos orgânicos baseados na arquitetura do tipo bulk heterojunction com uma camada ativa composta por P3HT e PCBM. Inicialmente foi efetuado um estudo na procura da melhor razão de massas entre os compostos orgânicos constituintes da camada ativa. Depois foi abordado um novo mecanismo de otimização baseado no tratamento térmico pós fabrico.
In the present work, the fabrication, characterization and optimization of organic photovoltaic devices was carried out based on the bulk heterojunction architecture, with an active layer made of P3HT and PCBM. Initially a study was done to find the best mass ratio between the organic compounds that constitute the active layer. After that, a new mechanism of optimization based on post fabrication annealing was approached.
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Alet, Pierre-Jean. "Cellules photovoltaïques en couches minces à base de silicium nanostructuré et de polymère semiconducteur." Palaiseau, Ecole polytechnique, 2008. http://www.theses.fr/2008EPXX0055.
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Cette thèse présente un travail exploratoire sur des cellules solaires hybrides, basées sur un matériau inorganique (le silicium) et un polymère (le P3HT). Cette structure a été imaginée pour améliorer les cellules à bas coûts à base de matériaux organiques. Nous démontrons ici sa faisabilité expérimentale et analysons son fonctionnement. L'hétérojonction entre le silicium et le P3HT a été étudiée sur des dispositifs en bicouches planes. Nous montrons qu'elle fournit de l'énergie électrique et que les deux matériaux peuvent contribuer au photocourant. Des rendements de 1,6 % ont été obtenus. Un effort constant a été fait pour simplifier et fiabiliser les procédés de fabrication. Deux nouveaux types de silicium nano-structuré ont été développés. Des ``nano-éponges'', dont la taille typique des pores est de 20 nm, ont été obtenues à l'aide de catalyseurs métalliques par dépôts assistés par plasma à 175 °C. Des nanofils de silicium ont été formés par un procédé inédit : les substrats sont des oxydes transparents conducteurs, les catalyseurs sont générés in situ et la température de croissance est inférieure à 300 °C. La phase würtzite a été mise en évidence dans certains fils, et divers modes de croissance ont été observés. Ces deux nouveaux types de couches minces pourront aussi être utilisées dans des cellules solaires inorganiquesThis thesis presents an exploratory work on a new design of hybrid solar cells, which are based on a junction between an inorganic material (silicon) and a polymer (P3HT). This structure is intended to improve the efficiency of organic based solar cells while maintaining low costs. Here, we investigate its experimental feasibility, and we analyze its performance. The hetero-junction between silicon and P3HT has been studied on bilayer devices. We have shown that this junction generates electrical power under illumination, and that both silicon and P3HT can contribute to the photocurrent. Power conversion efficiencies up to 1. 6% have been obtained. A large amount of work has been done to simplify the fabrication process and to improve its reliability. Two new nano-structured silicon layers have been developed. “Nanosponge” layers, where the typical dimension of pores is 20nm, have been obtained by metal-catalyzed plasma-enhanced CVD at 175C°. Silicon nanowires have been grown by a completely new process: the substrates are transparent conductive oxides, the catalysts are generated in situ, and the growth temperature is below 300C°. The würtzite (Si-IV) phase has been identified in some wires, and various growth modes are observed. Both kinds of layers may also find applications in inorganic solar cells
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Al-Busaidi, Zakiya Nasser Khalfan. "Enhanced lifetime of organic photovoltaics based on P3HT: PCBM." Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12435/.
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The short lifetime of organic photovoltaics (OPVs) is a key factor that limits the commercialization of this flexible, low-cost PV technology. The sensitivity of OPVs to water and oxygen in the ambient environment has been found to be the major reason for their degradation. Therefore, techniques to protect the devices from water and oxygen are needed. This thesis introduces new methods designed to reduce the impact of water and oxygen on the lifetime of OPV devices. Two different methods were developed, both using insulating polymers. The first was the addition of an insulating polymer, such as poly (methyl methacrylate) (PMMA), or poly (ethylene glycol) (PEG), to a poly (3-hexylthiophene): [6, 6]-phenyl-C61-butyric acid methyl ester (P3HT: PCBM) OPV blend (ternary approach). It was found that this technique increased the lifetime of the OPVs, due to the ability of the insulating polymers to work as gettering agents for water. The second method that was used is laminating OPVs with an insulating polymer. It was found that this lamination technique enhanced the device lifetime more than the ternary approach due to the creation of a barrier to the ingress of both oxygen and water.
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Freisinger, Birger [Verfasser]. "Investigation of P3HT PCBM particle-based solar cells / Birger Freisinger." Mainz : Universitätsbibliothek Mainz, 2013. http://d-nb.info/1036317927/34.
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Kumar, Avinesh Avi. "Charge transport in semi-crystalline poly(3-hexylthiophene) (P3HT) structures." Thesis, Queen Mary, University of London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538659.
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Desta, Derese Gugsa. "Study of air-processed Si-NC/P3HT hybrid solar cells." Master's thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/6451.
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Mestrado em Ciência e Engenharia dos MateriaisNeste trabalho são estudadas células solares híbridas formadas por poli(3- hexiltiofeno-2,5-diyl) (P3HT) como condutor orgânico de buracos e nanocristais de silício (Si-NCs) como conductor de electrões inorgânico. Células solares híbridas têm atraído muita atenção nos últimos anos devido ao facto de serem potencialmente fabricadas a baixo custo, a sua flexibilidade e baixo peso. As possibilidades de processamento em solução e ajuste da região espectral de absorção, a baixa toxicidade, e a abundância fazem dos Si-NCs um material atractivo para aplicação em células solares. Si-NCs de elevada qualidade podem hoje em dia ser produzidos em larga escala a partir da fase gasosa através da decomposição de silano num plasma. Embora a superfícies destes Si-NCs seja terminada com ligações Si-H durante a sua síntese, estes desenvolvem uma camada de óxido na superfície quando são expostos ao ar. Até agora, células híbridas de Si-NC/P3HT foram fabricadas com Si- NCs que não foram expostos ao ar após a sua síntese e foram posteriormente estudadas em condições de atmosfera inerte, devido à expectativa de que a exposição ao ar resulta na sua degradação. No entanto, o processamento de dispositivos em atmosfera inerte impõe limitações em termos técnicos e custo. Nesta tese estudamos o efeito do processamento em atmosfera de ar na performance e degradação de células solares híbridas de Si-NC/P3HT. As células foram fabricadas em ar e em atmosfera de azoto e caracterizadas à temperatura ambiente e condições de exposição ao ar. Para produzir a células solares foram usados Si-NCs que foram expostos ao ar após a síntese e que por isso contêm uma camada de óxido na sua superfície. Para remover esta camada, nós usamos um método de erosão química com uma solução diluída de ácido hidroflurico (HF). Células solares fabricadas com uma mistura de 1:1 em percentagem de peso (wt.%) de Si-NC:P3HT não revelaram qualquer efeito fotovoltaico. Dispositivos fabricados com uma mistura de 2:1 wt.% de Si-NC:P3HT mostraram efeito fotovoltaico, devido à formação de uma rede interpenetrara de Si-NC e P3HT em toda a extensão do filme foto activo, tal como revelado em imagens de microscopia electrónica de varrimento. Dispositivos fabricados em atmosfera inerte não revelaram uma performance melhorada em relação aos dispositivos produzido em atmosfera de ar, indicando que a fabricação das células solares em ar não é o factor determinante da performance das nossas células solares. Células solares que mostraram um efeitos fotovoltaico degradaram-se rapidamente por exposição ao ar. Em contrate, filmes de P3HT e de misturas Si-NC/P3HT, estudados em experiências separadas, não revelaram uma degradação significativa por exposição ao ar. Estes resultados indicma que a degradação das células solares não deve resultar da degradação da camada foto activa de Si-NC/P3HT, mas poderá resultar da degradação de interfaces entre as varias camadas que compõem as células. Medidas de ressonância paramagnética electrónica (RPE) foram levadas a cabo com os Si-NCs usados nas nossas células e com Si-NCs usados para fabricar as células estudadas em trabalhos publicados anteriormente por outros grupos. Estas medidas revelaram que o número de defeitos superficiais por nanocristal nos nossos Si-NCs é cerca de três ordens de grandeza superior ao número encontrado nos Si- NCs usados anteriormente. Este facto poderá explicar a baixa performance fotovoltaica os nossos dispositivos.
We study-air-processed organic-inorganic hybrid solar cells, which incorporate poly(3-hexylthiophene-2,5-diyl) (P3HT) as organic hole conductor and silicon nanocrystals (Si-NCs) as inorganic electron conductor. Hybrid solar cells have received a lot of attention in recent years due to their low cost, flexibility and lightweight. Solution processability, nontoxicity, abundance and tunable absorption spectral range of Si-NCs make them attractive materials for application in solar cells. High quality Si-NCs can now a days be produced in large amounts from the gas phase decomposition of silane in a plasma. Although the surface of these Si-NCs is terminated with Si-H bonds immediately after synthesis, they develop an insulating native oxide shell after being exposed to air. So far, Si-NC/P3HT hybrid solar cells have only been fabricated using Si-NCs that have not been exposed to air after synthesis and afterwards characterized under inert atmosphere conditions due to the expectation that air exposure of the devices leads to their degradation. However, inert atmosphere processing has some technical and cost efficiency limitations. In this thesis, we study the effect of air-processing on the performance and degradation of solar cells based on Si-NC/P3HT. Hybrid solar cells were fabricated in air and under nitrogen ambient and characterized at room temperature under atmospheric air. To produce our solar cells we use Si-NCs that have been stored in air after plasma synthesis and, therefore, contain a native oxide at their surface. To remove this oxide layer we apply wet etching with a dilute hydrofluoric acid (HF) solution. Solar cells made from 1:1 wt.% (HF-etched Si-NC:P3HT) composition did not show detectable photovoltaic effect. A very small photovoltaic effect has been observed for devices made from 2:1 wt.% (HF-etched Si-NC:P3HT) composition as a result of the formation of an interpenetrated network throughout the photoactive film at higher NC concentration as seen from scanning electron microscopy. Device fabrication under inert atmosphere did not result in improved solar cell performance. This shows that fabrication of the devices in air was not the main reason for the poor performance of the hybrid solar cells. Moreover, solar cells that exhibited a photovoltaic effect were found to degrade within one day of air exposure. In contrast to this, the conductivity of P3HT, (unetched Si-NC)/P3HT and (HF-etched Si-NC)/P3HT films, studied in separate experiments, did not show significant degradation upon air exposure. These results indicate that the degradation of the solar cells is not due to degradation of individual photoactive layers, but could rather originate from degradation of interfaces between the different layers. Electron paramagnetic resonance measurements carried out with our Si- NCs and with Si-NCs used in previous investigations of Si-NC/P3HT solar cells revealed that the number of surface defects per NC is about three orders of magnitude larger in our NCs than in those used in the previous investigations. This could be a reason for the poor performance of our Si- NC/P3HT hybrid solar cells.
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Liu, Jiang. "P3HT:PCBM Bulk Heterojunction Organic Solar Cell : Performance Optimization and Application of Inkjet Printing." Thesis, Linköping University, Department of Science and Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-14987.
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Organic solar cells have emerged as an important cheap photovoltaic technology. In this thesis work, a study of P3HT:PCBM heterojunction solar cells was presented. By incorporation of photo-active film slow growth, PEDOT:PSS (Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)) de-water treatment and application of highly conductive PEDOT:PSS (HC-PEDOT), a maximum PCE (power conversion efficiency) of 4% was achieved.
Inkjet printing technique was on the other hand introduced into fabrication process. The morphological, electrical and optical properties of printed HC-PEDOT were investigated. Fine silver girds with well-designed pattern, combining with a transparent thin film of HC-PEDOT, was inkjet-printed to form the anode of solar cells. A functional device with printed anode and printed photo-active layer was demonstrated, showing the possibility of realizing fully printed organic solar cells.
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Reis, Gisele Alves dos. "Análise das propriedades óticas do poli( 3-metiltiofeno) (P3MT) sintetizado eletroquimicamente." Universidade Estadual de Londrina. Centro de Ciências Exatas. Programa de Pós-Graduação em Física, 2009. http://www.bibliotecadigital.uel.br/document/?code=vtls000151292.
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Os semicondutores orgânicos possuem características físicas bastante parecidas com as dos semicondutores inorgânicos, podendo ser utilizados na fabricação de LEDs, células fotovoltaicas e lasers. Os polímeros semicondutores apresentam as seguintes vantagens sobre os semicondutores inorgânicos: (a) maior flexibilidade e maleabilidade; (b) a possibilidade e facilidade de realizar pequenas mudanças estruturais no monômero do polímero de forma a alterar as propriedades físicas e químicas; (c) a simplicidade das técnicas de fabricação e (d) o baixo custo de produção. Dentre os poli(3-alquiltiofenos) (P3AT), o poli(3-metiltiofeno) (P3MT) tem potencialidade como dispositivo emissor de luz. Politiofenos e derivados tem uma boa estabilidade química em condições ambientais, produzindo assim interfaces estáveis com eletrodos metálicos comumente utilizados em eletrônica. O P3MT foi sintetizado eletroquimicamente através da oxidação do monômero, 3-metiltiofeno, utilizando uma cela com três eletrodos e uma solução constituída do monômero e do eletrólito LiClO4 ou Et4NBF4 em acetonitrila. Os filmes poliméricos foram depositados sobre os substratos condutores transparentes de óxido de estanho dopado com flúor (FTO). Como eletrodo auxiliar foi utilizado uma placa de platina e como eletrodo de referência foi utilizado Ag/AgCl. Os filmes foram analisados por espectroscopia no infravermelho (FTIR), ressonância paramagnética eletrônica (EPR), espectroscopia de absorção por refletância no ultravioleta-vísivel (UV-VIS) e espectroscopia de fotoluminescência (PL). Os espectros de FTIR apresentaram as freqüências características do P3MT e, juntamente com os resultados de EPR, possibilitaram caracterizar os portadores de carga e identificar estruturas benzênicas e quinônicas na formação das cadeias do P3MT devido à dopagem do material. Os espectros de absorção UVVis possibilitaram a obtenção do gap de energia médio do P3MT e apresentaram a banda de transição _-_* e uma banda de bipólaron. Nos espectros de PL, com variação da potência de excitação e da temperatura, foram realizados estudos através de ajustes com gaussianas, considerando a forte probabilidade da existência de duas contribuições distintas de emissão na formação dos espectros. Estas duas contribuições foram atribuídas à emissão das cadeias mistas (gaussiana centrada em maior energia) e a emissão das cadeias benzênicas (gaussiana de menor energia) presentes no material polimérico formado.Organic semiconductors have physical characteristics very similar to those of inorganic semiconductors, which can be used in the manufacture of LEDs, photovoltaic cells and lasers. Semiconductor polymers have the following advantages over inorganic semiconductors: (a) greater flexibility and malleability, (b) the possibility and easiness of perform small structural changes in the monomer of the polymer in order to change the physical and chemical properties, (c) the simplicity of the techniques of manufacture and (d) the low cost of production. Among the poly(3-alquiltiofenos) (P3AT), the poly(3-methylthiophene) (P3MT) has potential as a light emitter device. Polythiophene and derivatives has good chemical stability in environmental conditions, thereby producing stable interfaces with metal electrodes commonly used in electronics. The P3MT was synthesized electrochemically through the oxidation of monomer, 3-methylthiophene, using a three electrodes cell and a solution with monomer and electrolyte LiClO4 or Et4NBF4 in acetonitrile. The polymeric films were deposited on transparent conductive substrates of fluorine tin oxide (FTO). A platinum sheet was used as auxiliary electrode and Ag/AgCl was used as reference electrode. The films have been analyzed by infrared spectroscopy (FTIR), electron paramagnetic resonance spectroscopy (EPR), UV-VIS absorption spectroscopy and the photoluminescence (PL). The FTIR spectra show the characteristic features of P3MT and, together with the results of EPR, allowed the characterization of the charge carriers and identify benzene and quinones in the formation of chains of P3MT due to doping of the material. The UV-Vis absorption spectra allowed to obtain the average gap energy of P3MT and presented the _-_* transition band and a bipolaron band. In the PL spectra, with variation of excitation power and temperature, studies were performed through the fit with Gaussian functions, given the strong probability of the existence of two distinct contributions in the formation of emission spectra. These two contributions were assigned to the emission of mixed chains (Gaussian centered at higher energy) and emission of benzenoid chains (Gaussian of lower energy) in the formed polymeric material.
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Mulderig, Andrew J. "Performance and Active Layer Morphology of P3HT-PCPDTBT Organic Photovoltaic Cells." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1457619609.
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Mougnier, Sébastien-Jun. "Copolymères semi-conducteurs à architectures variées : de l'ingénierie macromoléculaire à l'électronique organique." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14675/document.
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A une époque où les technologies nouvelles fleurissent chaque jour, un domaine particulier se détache : l’électronique organique. Par son utilité et sa facilité de mise en œuvre, l’électronique organique affiche de grandes promesses pour l’avenir. Dans le but d’améliorer le procédé de fabrication et la durée de vie de ces dispositifs, le travail de cette thèse s'est focalisé sur la synthèse de copolymères à architectures variées à base de poly(3-hexylthiophène) (P3HT). Après avoir exposé les problématiques et objectifs de la thèse dans une première partie, la synthèse de différents précurseurs P3HT est décrite. Ces matériaux représentent la base des travaux présentés dans cet ouvrage. Dans un premier temps, l'optimisation de la synthèse des copolymères à blocs rigide-flexible a été réalisée en suivant une stratégie adaptée pour une application en électronique organique. La conception de nouveaux matériaux semi-conducteurs à architectures ramifiées est traitée par la suite. Enfin, le dernier chapitre porte sur l'intégration d’un copolymère, le P3HT-b-Poly(4vinylpyridine), en cellule photovoltaïque organique en tant qu'additif de la couche active. Cette approche s’avère être particulièrement puissante, permettant notamment de diminuer le temps et le coût énergétique de la mise en œuvre de ces cellules en s’affranchissant d’une étape clé de la fabrication, le recuitAt a time when new technologies emerge every day, a specific domain stands out: the organic electronic. Through its low cost processing or even its utility, the organic electronic constitutes a very promising future.In order to improve the fabrication process and the lifetime of the devices, the work of this thesis was focused on the synthesis of copolymers with various architectures based on poly(3-hexylthiophene) (P3HT). After a first part where main issues and objectives are presented, the synthesis of different P3HT-based precursors is described in a part which could be considered as the heart of these works. Starting with appropriated precursors, the optimization of rod-coil diblock copolymer synthesis was performed following a strategy designed specifically for organic electronic application. Moreover, the precursors were used for the conception of new semi-conducting materials with a variety of architectures, such as graft and star copolymers. Finally, the last part deals with the integration of the P3HT-b-Poly(4-vinylpyridine) copolymer into organic solar cell as an additive of the active layer. This approach turns out to be powerful, especially allowing decreasing the time and the energy cost by avoiding the key step of the fabrication process of those devices, the annealing step
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Ozório, Maíza da Silva [UNESP]. "Estudo de compósitos de tips-pentaceno para aplicações em transistores." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/152818.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Um dos atuais desafios da eletrônica orgânica é a obtenção de semicondutores com alta mobilidade que forme filmes com boa morfologia quando depositado/impresso por solução, resultando em boa uniformidade e reprodutibilidade dos dispositivos. O poli(3- hexiltiofeno) (P3HT) e o 6,13-(triisopropilsililetinil)pentaceno (TP) estão entre os semicondutores orgânicos mais utilizados. O TP tem como característica a formação de estruturas cristalinas, e desse modo, apresenta mobilidade muito maior que o P3HT, no entanto é difícil de obter filmes com boa morfologia e resultados reprodutíveis. Visando um material semicondutor que apresente mobilidade significativamente melhor que a do P3HT e uma morfologia melhor que a do TP, estudou-se compósitos a partir da mistura destes materiais (P3HT:TP) para aplicação em transistores orgânicos de efeito de campo (OFETs), utilizando óxido de alumínio anodizado (Al2O3) tratado com HMDS como dielétrico de gate. Para análise da morfologia dos compósitos semicondutores de P3HT:TP usou-se microscopia eletrônica de varredura (MEV), microscopia de força atômica (AFM) e microscopia óptica (MO). Análise óptica foi feita através de medidas de fotoluminescência (PL) e de tempo de decaimento por fotoluminescência. Espectroscopia Raman e FTIR foram utilizadas para análises estruturais. No modo transistor a caracterização foi feita através de curvas de saída e transferência. Através das caracterizações elétricas determinou-se os parâmetros do semicondutor, tais como, mobilidade, voltagem limiar de chaveamento e razão entre o estado ligado e desligado. A morfologia da blenda semicondutora apresentou características específicas de cada material, ressaltando a formação de aglomerados. Observou-se diferenças bastantes consideráveis na morfologia do compósito em função da variação do solvente e da cinética de deposição dos filmes. Imagens de MEV mostram regiões cristalinas do TP dispersas na matriz polimérica do P3HT, onde o tamanho, forma e distribuição dos cristalitos dependem do tratamento dado à superfície do isolante. O aumento da concentração de TP dificulta a formação de compósitos com boas características. A melhor mobilidade foi obtida com o compósito 50P3HT:50TP, apresentando valores na ordem de 10- 3 cm2V -1 s -1 .
One of the current challenges of organic electronics is the development of semiconductors with high mobility to form films with good morphology when deposited/printed by solution, resulting in good uniformity and reproducibility of the devices. The poly (3-hexylthiophene) (P3HT) and 6,13-(triisopropilsililetinil)pentacene (TP) are among the most widely used organic semiconductors. The TP films are constituted by crystalline lamellar structures, and thus has greater mobility than the P3HT, however, it is difficult handling it to obtain films with good morphology and reproducible results. Targeting a semiconductor material with significantly better mobility than that of P3HT and better morphology than that of TP, we studied composites of these materials (P3HT: TP) for using in organic field effect transistors (OFETs). The transistor was prepared depositing the solution of the semiconductor composite, by spin coating, on the aluminium oxide, obtained by anodization and treated with HMDS, followed by the thermal evaporation of gold on the top, to form the drain and source electrodes. For analysis of the morphology of the composites semiconductors (P3HT: TP) was used scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical microscopy (OM). Optical analysis was performed using photoluminescence (PL) measurements and decay time by photoluminescence. FTIR and Raman spectroscopy were used to structural analysis. In mode transistor, characterization was performed using output and transfer curves. Through the electrical characterizations determined the semiconductor parameters such as mobility, threshold-switching voltage and the ratio between the current in “on” and “off” states. The morphology of the semiconductor composite presented specific characteristics of each material, emphasizing the formation of agglomerates. It has been observed quite considerable differences in the morphology of the composite depending on the solvent and the variation of the film deposition kinetics. SEM images show crystalline regions TP dispersed in the polymeric matrix of P3HT, where the shape, size and distribution of crystallites depend on the treatment of the surface of the dielectric. The increase in TP concentration hinders the formation of composites with good characteristics. The best mobility was obtained with the composite 50P3HT: 50TP, with values in the order of 10- 3 cm2V -1 s -1 .
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Van, Heerden Brian Abraham. "Charge transfer efficiency and optical properties of P3HT/PCBM spin coated thin films." UWC, 2009. http://hdl.handle.net/11394/2731.
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>Magister Scientiae - MScThe efficiency of organic photovoltaics is influenced by the structure of the polymer, the morphology of the film, the interfaces between the layers, the choice of electron acceptor material and the ratio between the electron acceptor material and the polymer. In this project, we have used regioregular poly (3-hexylthiophene) (rr-P3HT) as the electron donor material and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), a derivative of the C60 fullerene, as the acceptor material. Different weight-ratios of rr-P3HT to PCBM were prepared by stirring for several hours in a chloroform solution and subsequently spin coated onto crystalline silicon and transparent conductive oxide/glass substrates. The effect of the PCBM concentration on the photo-induced optical emission and absorption properties of rr-P3HT was investigated by photoluminescence and ultraviolet-visible spectroscopy, respectively. Changes in the structural properties, as a function of the weight-ratio, were probed by high-resolution transmission electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy. Results show that the structural integrity and crystallinity of rr-P3HT is compromised with the addition of excessive amounts of PCBM, which has a negative impact on the optical absorption of rr-P3HT and the photo-induced charge transfer mechanism between the rr-P3HT and PCBM. This work illustrates that blending rr-P3HT with an equal weight of PCBM results in an optimum configuration for improved performance in organic photovoltaic devices.
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Skypnychuk, Vasyl. "Fabrication of hybrid solar cells based on P3Ht, Zinc Oxide and carbon Nanotubes." Master's thesis, Universidade de Aveiro, 2010. http://hdl.handle.net/10773/9785.
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Mestrado em Ciência e Engenharia dos MateriaisRecentemente tem-se vindo a registar um interesse significativo no estudo de células fotovoltaicas híbridas devido ao facto da tecnologia requerida para o ser simples e flexível, o que associado a uma eficiente capacidade de conversão da energia solar as tornará economicamente viáveis. A utilização de nanopartículas inorgânicas veio aumentar o potencial interesse neste campo já que os efeitos de confinamento quântico associados ao reduzido tamanho das partículas tem permitido aumentar a eficiência deste tipo de células. Neste trabalho, foram estudadas células fotovoltaicas híbridas à base de poli(3-hexiltiofeno) (P3HT) e nanopartículas de ZnO. Utilizaram-se nanopartículas de ZnO com e sem modificação superficial com o ácido pireno- 1-carboxílico (PCA). Adicionalmente foi ainda estudado o efeito de nanotubos de carbono (CNT) comerciais e de florestas de CNT preparadas por deposição química em fase vapor (CVD), sobre o comportamento dos nanocompósitos de P3HT/ZnO. As nanopartículas de ZnO foram sintetizadas e caracterizadas por SEM, DLS e por espectroscopia no UV-Vis, no IV e de fotoluminescência. A morfologia dos filmes compósitos de P3HT, nanopartículas de ZnO (modificadas ou não) e CNT (componentes da camada activa) foi analisada por SEM. Verificou-se que a modificação superficial das nanopartículas de ZnO com PCA levou a uma ligeira melhoria da sua dispersão na matriz de P3HT, nomeadamente no caso dos nanocompósitos contendo CNT. As propriedades ópticas destes materiais foram estudadas por espectroscopia no UV-Vis e de fotoluminescência. As células solares híbridas foram preparadas com a seguinte configuração: Vidro/ITO/PEDOT:PSS/camada fotoactiva/Al. As suspensões de PEDOT:PSS bem como das camadas fotoactivas foram depositadas por spin-coating sobre um substrato de vidro revestido com ITO, sendo por fim depositada uma camada de alumínio por evaporação térmica. A caracterização dos dispositivos foi feita através de medições de correntetensão sob condições simuladas de iluminação padrão. Apesar da adição de CNT ter levado a um aumento significativo da densidade de corrente, a maioria das células fotovoltaicas preparadas não apresentou actividade fotovoltaica. Por fim, são discutidos possíveis factores que poderão ser responsáveis pelo desempenho insatisfatório dos dispositivos preparados e propostas algumas sugestões para trabalho futuro.
An ever growing interest is now focused on the development of hybrid solar cells as potentially cheap, easy and efficient technology for solar energy conversion. Specifically, the application of inorganic nanoparticles for this purpose can boost cell efficiency due to the particle size-related effects. In the present work, hybrid solar cells based on poly(3-hexylthiophene) (P3HT) and ZnO nanoparticles were investigated. Both unmodified and surfacemodified with pyrene-1-carboxylic acid (PCA) nanoparticles of ZnO were used Additionally, the effect of carbon nanotubes on the properties of P3HT/ZnO composites was tested. Both pristine and CVD-grown carbon nanotubes were applied. ZnO nanoparticles were synthesized and characterized by SEM, DLS, and UVVis, photoluminescence and IR spectroscopies. The morphology of the films of different composites prepared using P3HT, ZnO nanoparticles and carbon nanotubes (active layer composites) was analyzed by SEM. Modification of ZnO nanoparticles with PCA lead to a slight improvement of their dispersion quality in P3HT which was further improved when carbon nanotubes were added to the P3HT / PCA-modified ZnO composite. The optical properties of the ensuing composite materials were studied by UV-Vis and photoluminescence spectroscopies. The hybrid solar cells with the structure Glass/ITO/PEDOT:PSS/active layer composite/Al were prepared by successive spin-coating of the corresponding suspensions on ITO-coated glass substrates, followed by deposition of an aluminium layer by thermal evaporation. The current-voltage characteristics of the cells were measured under simulated standard illumination conditions. Although the addition of carbon nanotubes yielded a significant increase in current density, most of the cells did not show any photovoltaic effect. Finally, possible factors responsible for the low efficiency of the cells prepared are discussed and some suggestions for future work are proposed.
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Xu, Yifan. "Studies on field effect transistors with conjugated polymer and high permittivity gate dielectrics using pulsed plasma polymerization." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124219179.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xx, 187 p.; also includes graphics (some col.). Includes bibliographical references (p. 174-187). Available online via OhioLINK's ETD Center
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Khlaifia, Dalila. "Conception, modélisation et nanostructuration de nouveaux dérivés du P3HT et composites pour la photoconversion." Thesis, Nantes, 2016. http://www.theses.fr/2016NANT4061.
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Ce travail de thèse s’inscrit dans le domaine en plein essor de l’Electronique Organique et Imprimée dont les domaines d’applications sont nombreux. Concernant la couche photoactive pour les dispositifs photovoltaïques, deux axes de recherche sont très actifs: (i) la conception de nouvelles molécules/polymères possédant des caractéristiques structurales et optoélectroniques améliorées (ii) la nanostructuration et l’hybridation de ces matériaux. Dans ce contexte, une première étude par modélisation a permis d’établir la relation entre structure et propriétés optiques des oligomères du 3-hexylthiophène (3HT) ainsi que celles du polymère P3HT par la théorie de la fonctionnelle de la densité (DFT), en s’appuyant sur une étude expérimentale récente de la littérature. Dans la seconde étude, de nouvelles molécules ont été modélisées à une fin de photoconversion améliorée via une stratégie de réseaux interpénétrés. Le comportement donneur-accepteur a été évalué pour six molécules à base d’entités 3HT couplées à diverses entités moléculaires puis associées au dérivé du fullerène PC61BM. L’objectif poursuivi est double : accroitre la gamme spectrale d’absorption et ajuster les niveaux d’énergie avec ceux du PC61BM. Parallèlement, une étude expérimentale de nanofibres composites P3HT-SWNT (nanotubes de carbone mono-parois) a été menée. Les effets de la nanostructuration par méthode template sur la structure et les propriétés optiques ont été déterminés, d’une part pour le P3HT regio-régulier, d’autre part pour le composite P3HT-SWNT. Une organisation remarquable des SWNT induite par l’orientation préférentielle des chaînes de P3HT dans les nanofibres a en particulier été obtenueThis PhD work deals with Organic and Printed Electronics in relation with photovoltaics. Concerning the photoactive material of photovoltaic devices, two ways of research and development are much investigated: (i) design of new molecules/polymers with improved structural and optoelectronic characteristics, (ii) nanostructuration and hybridization of such materials. In this context, a first study focused on establishing the relationship between the structure and the optical properties of 3-hexylthiophene (3HT) oligomers and the corresponding polymer P3HT with a modeling approach by the density functional theory (DFT). This study was supported by experimental results reported recently in the literature. In a second study, new molecules have been designed and modeled with a target of improved photoconversion by using an interpenetrating network. The donor-acceptor behaviour was evaluated for six new molecules based on 3HT entities coupled to different molecular species and then associated to PC61BM, a fullerene derivative. The purpose was double: to increase the spectral range of absorption and to optimize the energy levels with those of PC61BM. At the same time, composite nanofibers of P3HT and single-walled carbon nanotubes (SWNT) were investigated experimentally. The effects of the nanostructuration on the structure and the optical properties by a melt-assisted template strategy have been determined on pure regio-regular P3HT and on composite P3HT-SWNT. A remarkable organization of the SWNT has been identified and attributed to a combined effect of the strong orientation of P3HT chains along the nanofibers, altogether with the self-assembly of SWNT with polymer chains
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Farouil, Léa. "Etudes théorique et expérimentale de semi-conducteurs organiques pour l'élaboration d'un biocapteur destiné à la détection de la pollution de l'eau." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30310/document.
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L'objectif de ce travail de thèse est l'élaboration d'une photodiode organique (OPD) destinée à être intégrée dans un biocapteur. Ce travail s'inscrit dans le cadre plus général de l'étude et de l'amélioration de composants organiques impliqués dans des microsystèmes de détection visant à surveiller la pollution de l'eau. Le besoin d'évaluation et de suivi de la qualité de l'eau suscite un grand intérêt pour des systèmes de détection portables de polluants ayant une réponse rapide et de faible coût. Le principe de la mesure repose sur la détection des variations de fluorescence de micro-algues en présence de substances toxiques. Excitées grâce à une diode électroluminescente (LED) bleue, les algues vont émettre un signal de fluorescence dont l'intensité, modifiée en présence de polluant (Diuron), est détectée par l'OPD optimisée. Le signal de fluorescence à détecter étant très faible, l'OPD idéale doit avoir un faible courant d'obscurité et une grande sensibilité. Cela passe par un choix judicieux des matériaux semi-conducteurs organiques (OSC) entrant dans l'élaboration de la couche active du composant. Pour accompagner le choix des matériaux, il est intéressant d'explorer leurs propriétés physico-chimiques tout en essayant de rationaliser les mécanismes mis en jeu au sein de ces matériaux lorsqu'ils sont utilisés dans l'élaboration d'OPD (phénomènes d'absorption de photons, mécanismes de transport de charges, et pertes associées aux recombinaisons de charges). Cette thèse s'articule autour de deux axes. Le premier axe consiste en une étude théorique qui vise à comprendre et à maitriser l'échange des charges à l'échelle nanométrique par des caractérisations optiques et des calculs de chimie quantique basés sur des méthodes DFT et TD-DFT. L'étude sur un système modèle (le P3HT) a permis d'établir un protocole de calcul très prometteur pour l'étude des propriétés de matériau d'intérêt, en particulier le PTB7. Le second axe est un volet à caractère expérimental. L'élaboration, la caractérisation et l'optimisation d'OPD à base de PTB7 : PC60BM a permis de concevoir un biocapteur algal apte à détecter le Diuron à des concentrations de l'ordre du nanomolaireThe aim of this thesis is to develop an organic photodiode (OPD) designed to be integrated into a biosensor. It is part of the broader framework of studying and improving organic components involved into devices devoted to water pollution monitoring. The need for such portable, fast-response, low-cost microsystems is of great interest. The measurement is based on the fluorescence detection of micro-algae under toxic substances exposure. The excited algae, under a blue light emitting diode (LED), will emit a fluorescence signal whose intensity, modified because of pollutant exposure (Diuron), is detected by the OPD. Since the fluorescence signal is very weak, the ideal OPD must have a low dark current and a high sensitivity. To achieve this performance, a judicious choice of organic semiconductor materials (OSC) used for the OPD is required. In addition, it is interesting to investigate their physico-chemical properties by rationalizing the mechanisms involved in the active layer (photon absorption phenomena, charge transport mechanisms, and losses associated with charge recombinations). This thesis is based on two axes. The first one consists in a theoretical study of the charge exchanges at a nanoscale. This have been done by both optical characterizations and quantum chemistry calculations based on DFT and TD-DFT methods. Calculations were performed on a model system (P3HT) thus providing the basis for a very promising computational protocol for studying the properties of materials of interest, for instance PTB7. The second axis concerns the experimental study of the OPD based on PTB7:PC60BM. We have developed, characterized and optimized an OPD guarantying the detection of algal fluorescence without and with Diuron at about nanomolar concentrations
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Amorim, Daniel Roger Bezerra. "Análise teórico-experimental sobre mecanismos de transporte em células solares orgânicas de P3HT e PCBM." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-11062018-115130/.
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As células solares orgânicas, também conhecidas como (OPVs), fazem parte da terceira geração dos dispositivos fotovoltaicos. Entre outras tecnologias emergentes, a dos OPVs tem a vantagem de ser de fácil processamento e de baixo custo. Ou seja, uma tecnologia comercialmente promissora na área de conversão de energia solar em energia elétrica. No entanto, grandes desafios precisam ser superados para colocar estas células no mercado dos fotovoltaicos. Dentre esses desafios, pode estar incluído, inevitavelmente, a compreensão dos processos físicos envolvidos na fotogeração em OPVs, dentre os quais pode-se destacar o da recombinação de cargas fotogeradas. A recombinação é o principal responsável pela perda de eficiência em OPVs, uma vez que ela elimina uma fração relativamente grande de portadores de carga, diminuindo consideravelmente a potência de saída da célula. Para estudar este efeito indesejado em células orgânicas, desenvolvemos um modelo analítico para fotocorrente em OPVs do tipo bulk heterojunction (BHJ), assumindo uma recombinação bimolecular de cinética de segunda ordem. O modelo é representado por uma expressão analítica obtida a partir das equações fundamentais da eletrodinâmica clássica, onde despreza-se a contribuição da corrente de difusão e as mobilidades dos elétrons e dos buracos são consideradas iguais. Essa expressão foi de grande valia na análise dos resultados experimentais, sobretudo os de corrente-tensão (J-V) sob iluminação, e além disso, ela permitiu extrair parâmetros intrínsecos do transporte de carga, como mobilidade e coeficiente de recombinação. Neste sentido, foram fabricados dispositivos cuja estrutura foi ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al, e com eles foram realizados inúmeros experimentos. As técnicas usadas na parte experimental foram: medidas J-V, no escuro e sob iluminação, medidas de transiente de fotovoltagem (TPV), de transiente de fotocorrente (TPC), e de Foto-CELIV (Charge Extraction Linear Increasing Voltage). Usamos como parâmetros experimentais a temperatura e intensidade de iluminação. Das medidas J-V sob iluminação, foram extraídos os parâmetros essenciais da célula: corrente de curto (Jsc), potencial de circuito aberto (Voc), fator de preenchimento (FF) e a eficiência (PCE). A partir das abordagens experimental e teórica, exploramos a influência da recombinação bimolecular no comportamento fotovoltaico dos dispositivos. O desenvolvimento do modelo teve contribuição de trabalhos que se basearam em modelagem numérica a partir de condições físicas semelhantes às usadas em nosso tratamento e que foram levadas em consideração no processo de análise dos resultados experimentais.Organic solar cells, also known as (OPVs), are part of the third generation of photovoltaic devices. Among other emerging technologies, OPVs have the advantage of being easy to process and exhibits low cost of production. That is, it is a promising commercial technology in the area of converting solar energy into electricity. However, major challenges need to be overcome to put these cells in the photovoltaic market. Among them, it can be included, inevitably, the comprehension of the physical processes involved in photogeneration in OPVs, of which, the recombination of photogenerated carriers is included. Recombination is primarily factor responsible for the loss of efficiency in OPVs, since recombination eliminates a large fraction of the carriers, considerably reducing the output power of the cell. To study this undesirable effect in organic cells, we developed an analytical model for the photocurrent in bulk heterojunction cells (BHJ), which assumes the bimolecular recombination of second order kinetics. The model is represented by an analytical expression obtained by the equations of the classical electrodynamics, where we neglected the contribution of the diffusion current and assumed that electrons and holes have equal mobilities. The expression was of great value for the analysis of the experimental results, especially the current-voltage (J-V) measurements under illumination, and it allowed to extract intrinsic parameters of charge transport effects, such as mobility and recombination coefficient. For this, it were fabricated devices whose structure was ITO/PEDOT:PSS/P3HT:PCBM/Ca-Al, and with them were performed numerous experiments. The techniques used in the experimental part were: J-V measurements, in the dark and under illumination, transient photovoltage (TPV), transient photocurrent (TPC), and of Charge Extraction Linear Increasing Voltage (Photo-CELIV). We used as experimental parameters the temperature and the intensity of. From J-V measurements under illumination we extracted the essential cell parameters: short current (Jsc), open circuit potential (Voc), fill factor (FF) and efficiency (PCE). From the experimental and theoretical approaches, we explored the influence of bimolecular recombination on the photovoltaic behavior of the devices. The development of the model had contributions of works based on numerical modelings from physical conditions similar to those used in our treatment and that were taken into account in the process of analysis of the experimental results.
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Cavallari, Marco Roberto. "Filmes de poli (3-hexiltiofeno) (P3HT) para transistores de filmes finos orgânicos utilizados como sensores." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-29122014-165104/.
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A importância da pesquisa em eletrônica orgânica, se comparada à microeletrônica convencional baseada principalmente em silício, surge pela presença de inúmeros semicondutores e técnicas de deposição de baixo custo e em grande superfície. Os Transistores de Filmes Finos Orgânicos (OTFTs, do inglês Organic Thin-Film Transistors) são a unidade fundamental em circuitos eletrônicos e, geralmente, apresentam a estrutura de um transistor de efeito de campo. Podem ser fabricados sobre substratos plásticos e oferecem grande número de aplicações como: mostradores, etiquetas de identificação por rádio frequência e eletrônica têxtil. Além disso, há demanda por componentes eletrônicos portáteis e baratos, principalmente como sensores em diagnósticos médicos e veterinários in-situ. A geometria de OTFT mais utilizada em sensores na atualidade é a bottom gate sobre substratos de silício altamente dopado e com óxido de porta inorgânico. Polímeros como poli(3-hexiltiofeno) (P3HT) vêm sendo amplamente utilizados pela comunidade científica, atestando o potencial comercial deste semicondutor em sensores. Neste contexto, esta tese apresenta o desenvolvimento de transistores à base de P3HT como sensores na detecção de analitos em fase vapor. O estudo é composto por uma etapa inicial de caracterização da mobilidade dos portadores de carga por técnicas de transiente de corrente, seguida pela otimização do desempenho de parâmetros elétricos do transistor através de alterações no processamento dos filmes dielétrico e semicondutor. Enfim, conclui-se a investigação através do entendimento dos fatores ligados à degradação do OTFT após exposição à atmosfera e sob estresse elétrico, além do detalhamento da sensibilidade e especificidade do sensor. Sensores de P3HT oferecem enorme potencial de detecção de amônia, cetonas e compostos organoclorados. Outros semicondutores poliméricos são provavelmente necessários para maior especificidade em relação a vapor dágua e álcoois.Research on organic electronics, compared to conventional silicon-based microelectronics, is necessary as it offers plenty of semiconductors and low-cost deposition techniques that can be performed over wide surfaces. Organic Thin-Film Transistors (OTFTs) are the fundamental unity in electronic circuits and, usually, display the metal insulator semiconductor field-effect transistor (MISFET) structure. OTFTs can be processed over cheap plastic substrates and integrate a high number of applications as: flexible displays, radio frequency identification tags, textile electronics and sensors (e.g. chemical and biological compounds). Nowadays, consumers demand portable and low-cost electronic devices, mainly as sensors for in-situ medical and veterinarian diagnosis. The most widely used OTFT structure in sensing is the bottom-gate/bottom-contact FET over highly-doped silicon substrates and inorganic dielectrics. Polymers as poly(3-hexylthiophene) (P3HT) have found increasing acceptance by the scientific community, attesting their potential as semiconductors for commercial applications. In this context, the thesis lies in the development of organic transistors based in P3HT polymer for the detection of vapor-phase compounds. This study begins with transistor performance optimization through changes in dielectric and semiconductor processing. Thin-film thickness and P3HT cast solution drying time are the main studied parameters. It involves also the understanding of device performance degradation when exposed to atmosphere and under bias stress, before finally mapping sensitivity and specificity against gaseous analytes. P3HT-based sensors are potentially interesting for ammonia, ketones and organochlorides detection. Other polymeric semiconductors may be necessary to increase specificity against water steam and alcohol analytes.
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Agumba, John O. [Verfasser], and Günter [Akademischer Betreuer] Reiter. "Formation and optical characterization of single crystals of poly(3-hexylthiophene)(P3HT), a model conjugated polymer." Freiburg : Universität, 2016. http://d-nb.info/1119717477/34.
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Manda, Venkata Ramana. "Enhancing the Photovoltaic Performance of P3HT/PDIB Silsesquioxane Donor-Acceptor System Using Spray Deposition Fabrication Technique." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1336.
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In the past few years, the solution-processed organic based solar cells gained more importance by meeting the demands for cost effective photovoltaic devices. To date, the focus of the organic photovoltaic devices has been on the optimization of the processing the materials to improve photo conversion efficiency and also by modifying the active components of the organic materials. Recently, it has been recognized that the deposition techniques also plays a major role in enhancing the power conversion efficiencies. Currently, though the most common deposition technique for organic solar cells is spin coating, which does not allow scaling up of the large device area. As an alternative method, a simple airbrush spray deposition technique has been developed to fabricate the test devices. The film thickness of the layers was characterized under scanning electron microscope. Devices with different thickness (1000 nm, 500 nm, 240 nm) of poly(3,4-ethylenedioxythipohene) polystyrene sulfonate (PEDOT.PSS) and active layers are prepared and their photovoltaic performances have been evaluated and compared by plotting the IV curves with respect to each thickness. Maintaining the distance between the substrate and the airbrush nozzle the thickness of the layers was controlled. From the results, we found that the test devices with 500 nm thickness of PEDOT.PSS and active layers shows the best device performance with highest current density of 3.97 mA/cm2, open circuit voltage of 1.3 V and power conversion efficiency of 2.34%. As a control experiment, devices were also developed using the standard poly(3- hexylthiophene-2,5-diyl):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) system, but the power conversion efficiencies of these devices were not promising with respect to the literature results. Future studies of this project will focus on improving the power conversion efficiency of poly(3-hexylthiophene-2,5-diyl)/perylenediimide bridged system (P3HT/PDIB) by developing a new device architecture called “tandem solar cells” which consists of multiple layers of different donor and acceptor blends with inorganic transition metal oxides such as zinc oxide and molybdenum oxides.
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Fernandes, Ricardo Vignoto. "Aplicação de materiais com luminescência deslocada para menores energias em dispositivos fotovoltaicos orgânicos de P3HT: PCBM." Universidade Estadual de Londrina. Centro de Ciências Exatas. Programa de Pós-Graduação em Física, 2018. http://www.bibliotecadigital.uel.br/document/?code=vtls000218367.
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Nas últimas décadas houve um grande aumento na pesquisa em dispositivos fotovoltaicos orgânicos, principalmente por proporcionarem uma alternativa de baixo custo para geração de energia elétrica. Entretanto, ao comparar células solares orgânicas com as inorgânicas mais tradicionais, é visto que a eficiência e a durabilidade ainda deixam a desejar. O objetivo desta tese é utilizar uma camada que contenha materiais luminescentes para aumentar a eficiência e a durabilidade de dispositivos fotovoltaicos orgânicos, através de um processo puramente óptico baseado no efeito de deslocamento da fotoluminescência (PL) para menores energias − do inglês luminescence down-shifting effect (LDS). Os materiais luminescentes, tanto individualmente quanto misturados, foram dispersos em uma matriz polimérica de PMMA, a qual é opticamente inerte para comprimentos de onda maiores que 300 nm. A escolha dos materiais foi baseada na posição de seus espectros de absorbância e de PL, considerando a curva de eficiência quântica externa (EQE) do dispositivo. Em um primeiro momento, o uso de camadas contendo misturas de materiais luminescentes levaram a um aumento relativo de aproximadamente 600% no tempo de vida da célula fotovoltaica, sem no entanto produzir um aumento significativo na eficiência da mesma. Foi então realizado um trabalho experimental de variação dos parâmetros de produção das camadas luminescentes, no sentido de aprimorar suas propriedades ópticas visando ao aumento da eficiência dos dispositivos. Com isso, foi possível obter uma camada que proporcionou um aumento relativo de 20% na densidade de corrente de curto circuito produzida pela célula, um resultado bastante satisfatório quando comparado com trabalhos anteriores.In the last decades there has been a great increase in the research on organic photovoltaic devices, mainly for providing a low cost alternative for electric energy generation. However, when comparing organic with the more traditional inorganic solar cells, it is seen that efficiency and durability are still lacking. The objective of this thesis is to use a layer containing luminescent materials to increase the efficiency and durability of organic photovoltaic devices, through a pure optical process based on the shifting of photoluminescence (PL) for lower energies − the so called luminescence down-shifting effect (LDS). The luminescent materials, both individually and in admixture, were dispersed in a polymer matrix of PMMA, which is optically inert at wavelengths greater than 300 nm. The choice of materials was based on the position of their absorbance and PL spectra, considering the external quantum efficiency (EQE) curve of the device. Initially, the use of layers containing mixtures of luminescent materials led to a relative increase of approximately 600% in the lifetime of the photovoltaic cell, however without producing a significant increase in its efficiency. Then, an experimental work was carried out by varying the production parameters of the luminescent layers, aiming to improve their optical properties in order to increase the efficiency of the devices. With this, it was possible to obtain a layer that provided a relative enhancement of 20% in the short-circuit current produced by the cell, a very satisfactory result when compared to previous works.
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Dupuis, Aurélie. "Caractérisation, optimisation et comportement photochimique de couches actives de cellules photovoltaïques organiques à base de poly(3-hexylthiophène)." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2012. http://tel.archives-ouvertes.fr/tel-00741958.
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Ce travail a été consacré à la caractérisation, l'optimisation et l'étude du comportement photochimique de couches actives de cellules photovoltaïques organiques. L'objectif était d'identifier les mécanismes de photovieillissement dans le but de proposer des stratégies pour améliorer la stabilité de cellules solaires organiques à base de Poly(3-hexylthiophène) (P3HT) et de [6,6]-phényl-C61-butanoate de méthyl (PCBM). Le premier axe de travail a été consacré à l'étude de l'influence des paramètres structuraux du P3HT (masse molaire, régiorégularité, pureté ...) sur sa stabilité photochimique dans un premier temps, puis sur l'optimisation des performances des cellules dans un second temps. Pour ce faire, quatre P3HT commerciaux différents ont été étudiés. Ils ont tout d'abord été caractérisés avec précision grâce à différentes techniques analytiques. La relation entre microstructure du P3HT et sa photostabilité a ensuite été étudiée, et les paramètres pertinents influençant la photodégradation identifiés. Le deuxième axe de travail a été consacré à la stabilité photochimique de mélanges P3HT:PCBM sur substrat inerte, puis sur des couches tampons. Dans une dernière partie, la dégradation de couches actives au sein de dispositifs complets a été effectuée en faisant " l'autopsie " de cellules vieillies.
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Su, Mo_Ting, and 蘇睦庭. "Studies of photovoltaic cell from conjugated polymer P3OT doped carbon nanosolids." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/04142513523909476638.
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碩士中原大學
應用物理研究所
93
Abstract In this thesis, we study the possibility of improvement of performance for organic photovoltaic cells by various dopants. The photovoltaic cell was primarily fabricated with conjugated polymer poly(3-octyl- thiophene) (P3OT), in conjunction with an additive based on singlewall carbon nanotubes (SWNTs), buckminsterfullerene (C60) or/and the nematic liquid-crystal E7. The samples include five constitutes: ITO/(P3OT+SWNTs)/Al, ITO/(P3OT+C60)/Al, ITO/(P3OT+E7)/Al, ITO/(P3OT+(E7+SWNTs))/Al and ITO/(P3OT+(E7+C60))/Al, and the doping concentration is chosen to be 1 wt%, 3 wt%, 5 wt% or 10 wt%. In view of photocurrent data, it is found that the samples doped with SWNTs perform poorly, likely due to the poor dispersion in the polymeric matrix. As anticipated, doping C60 can promote the photocurrent signal of the samples. The performance in photoconduction for the samples doped with E7 is the best among all samples investigated. From the experimental results of fluorescence spectra, we believe that the mechanism for the dopant E7 in the photoconducting polymer is different from that of carbon nanotubes or C60. We propose that the doapnt E7 may locally help polymeric molecules arrange more orderly and promote charge-carrier transport, leading to the higher photocurrent observed.
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Lin, Ying-Cheng, and 林穎成. "P3HT/TiO2 nanocomposite based on benzaldehyde end-functionalized P3HT and amphiphilic P3HT block copolymer." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/12384344491639221951.
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碩士國立臺灣大學
材料科學與工程學研究所
102
In this thesis, we reported the preparation, the microstructures and the optical properties of poly(3-hexylthiophene)/TiO2 nanocomposites based on aldehyde end-functionalized P3HT (P3HT-CHO) and amphiphilic P3HT block copolymer, poly(3-hexylthiophene-block-hydroxylated isoprene) (P3HT-b-PIOH). Pristine unmodified P3HT were also used for reference studies. Two methods were employed to prepare the Nanocomposites: (1) solution blending of polymers and commercial available TiO2 nanoparticles, Degussa P25 (~21 nm); (2) in-situ sol gel process of TiO2 precursors in polymer solution. The attractive interaction between aldehyde of P3HT-CHO and hydroxyl group of TiO2 allowed smaller aggregations of TiO2 (~ 50 - 200 nm) blending.The in-situ sol gel processes using chlorotitanium triisopropoxide (ClTIP) would further enhance the homogeneity in TiO2 dispersion despite of enlarged particle sizes (~ 50 -200 nm) as the aldehyde group of P3HT-CHO would react with ClTIP to form covalent bonds to anchor P3HT in the surface of TiO2. Thus preventing the aggregation of TiO2. Since the in-situ sol gel process avoid the use of dispersants and ligands of TiO2 nanoparticles, the photoluminescence quenching of P3HT-CHO/ClTIP composites could be further improved comparing to P3HT-CHO/P25. The use of amphiphilic P3HT-b-PIOH block copolymer remarkably afforded the resulting P3HT-b-PIOH/ClTIP composites having uniformed TiO2 nanoparticles (~ 30 nm) homogenously dispersed in the polymer matrix, which could be attributed the increasing number of covalent linkages between the hydroxyl groups of PIOH and ClTIP. The optical properties were derived from the UV-vis spectroscopy. Even the loading of TiO2 was up to 30 wt%, the maximum absorption peak was not blue-shifted and the π-π stacking of P3HT retain for P3HT-CHO/ClTIP and P3HT-b-PIOH/ClTIP composites
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Han-WenChan and 詹涵雯. "Fabrication of P3HT/Gold Nanoparticles LB Films by P3HT Templating Langmuir Monolayer." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/91485576767826224805.
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碩士國立成功大學
化學工程學系碩博士班
98
Regioregular poly-(3-hexylthiophene)(rr-P3HT) and mixed P3HT/ octadecylamine(ODA) was used as template monolayers to adsorb the gold nanoparticles (AuNPs) dispersed in subphase. Furthermore, the adsorption of AuNPs was enhanced by the destabilization effect of ethanol and CaCl2 introduced into the colloidal solution. The behaviors of the P3HT/AuNPs mixed films were studied by the pressure-area (π-A) isotherm and by the observations of transmission electron microscopy (TEM) and atomic force microscope (AFM). The experimental results show that P3HT do not form a homogeneous monolayer and tends to aggregate at the air/liquid interface. Meanwhile, the AuNPs adsorbed by the P3HT monolayer are low, attributable to the short interaction distance between AuNPs and P3HT. The introduction of ethanol and CaCl2 into the colloidal solution can increase the adsorbed amount of AuNPs, decrease the aggregation structure of P3HT, and leads to a more homogeneous P3HT/AuNPs monolayer. In addition, the introduction of ODA in the P3HT monolayer can also decrease the aggregation of P3HT molecules and enhance the incorporation of AuNPs into the monolayer.
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Chen, Sheng-Nan, and 陳勝南. "The morphology, microstructure and photophysical properties of P3HT and P3HT/PCBM electrospun fibers." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/07929660397149390761.
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碩士崑山科技大學
材料工程研究所
100
In this work, we provided insights into the morphology, microstroctore and photophysical properties of Poly(3-hexylthiophene) (P3HT) and blended P3HT with different contents of phenyl-C61-butyric acid methyl ester (PCBM) (P3HT/PCBM) fibers through the optical microscope (OM), polarized optical microscope (POM), scanning electron microscope (SEM), differential scanning calorimeter (DSC), Wide angle X-ray Diffraction (WAXD), UV-vis absorption (UV-vis) and photoluminescence (PL) spectra. In the second chapter, OM and SEM showed that a uniformly morphology with diameter ac. 200 nm electrospun P3HT fibers prepared by higher concentration of P3HT and higher voltage power supply. The result of POM presented that a cleanly birefringence image of electrospun P3HT fibers attributed high orientation P3HT polymer chain were packed and aligned along the fiber axes. Therefore, results of photophysical properties; such as UV-vis and PL spectra, indicated that the absorption efficiency and photoluminescence of P3HT fibers larger remarkably and smaller seriously, respectively, than that of P3HT thin film and semi-dilute solution meant that a significant energy transfer was presented due to the high orientation P3HT polymer chain were packed and aligned along the fiber axes within the nanofibers. Our results demonstrated that the morphology and photophysical properties of electrospun P3HT fibers have tunable by directly electrospinning technique. However, the result of WAXD indicated that the microstructure of P3HT electrospun fibers show the (100)、(200)、(300) and (020) diffraction planes of P3HT Type I crystalline and a diffraction peak at 21.28o for P3HT Type II crystalline. It meant that the microstructure of P3HT electrospun fibers was conbined major part amorphous structure of Type I and minor part Type II crystals in fibers, Finally, the diffraction peaks of P3HT nanofibers shifted to lower diffraction angle than that of P3HT thin film attributes the d-space between thiophene rings in Type I crystal within the P3HT fibers is larger than that within P3HT thin films. Therefore, the thermal behavior of P3HT electrospun fiber showed a lower nelting temperature but multi-melting endothermic peaks at Tm-II = 218 °C, Tm-I = 225 °C, respectively, comparaed with higher melting temperature and single endothermic peak of P3HT thin-film. In the third chapter, we provided insights into effects of the PCBM content on the morphology, microstroctore and photophysical properties of P3HT/PCBM fibers. However, the OM and SEM showed that the morphology of electrospun P3HT fibers from a uniformly to spindle-like and drops-shape fibers as PCBM content was increased. This maybe due to decreases in the content of P3HT and entanglement between P3HT chains in the P3HT/PCBM solution. The result of POM also presented that reduced in the birefringence of electrospun P3HT fibers with increasing PCBM content. The result of UV-vis spectrum indicated that the absorption efficiency of P3HT/PCBM fibers rised remarkably as PCBM increased. Moreover, in the normalized UV-vis spectrum indicated that the increase in absorption intensities at wavelength c.a. 200-300、350 and 650nm corresponded to the absorption efficiency of PCBM in P3HT/PCBM nanocomposity. Finally, the DSC profile indicated that the melting peck from 230.2°C (perfect crystalline) to 208.4°C (imperfect crystalline) means that the perfecticity and size of P3HT crystal was decreased with increasing PCBM. Therefore, the WAXD profile indicated that the microstructure of P3HT electrospun fibers show the (100)、(200)、(300) and (020) diffraction planes of P3HT Type I crystalline and a diffraction peak of P3HT Type II crystalline. The WAXD profile showed a borad diffraction peaks at 2?? ca. 17o~21 o for PCBM amorphous scattering at lower PCBM content; whereas the WAXD profile presented some diffraction peaks at ca. 3.48o、7.32 o、20.06o、21.86o and 23.1o attribute to the PCBM crystalline. The intensity of the diffraction peaks of PCBM crystalline in P3HT/PCBM fibers lower than that in P3HT/PCBM thin-film meaned that the aggregate or assemble of PCBM molecules in P3HT/PCBM thin-film were larger than that in P3HT/PCBM fibers due to phase-separation driving force during electorspping process.
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Chen, Deng-wei, and 陳登暐. "The Study of Organic Solar Cell incorporating Bromined-P3HT︰P3HT︰PCBM as Active Layer." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/50878779877565450246.
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碩士國立中山大學
光電工程學系研究所
98
Based on the solar cell’s four characteristic parameter open-circuit voltage (Voc) makes the discussion.The study of the relation VOC’s paper uses empirical formula. VOC’s formula is “VOC=(1/e)(｜EDonorHOMO︱-｜EAcceptorLUMO︱)-0.3V”. We can know that VOC related to donor material’s HOMO and acceptor material’s LUMO, if we need a high VOC, it can change the structure of donor material to have higher HOMO value, as well as the acceptor material have lower LUMO value. Our active layer except poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-Butyric acid methyl ester (PCBM), the third material was blended to discuss their effect on the VOC. Two kind of different bromined-P3HT (Br-P3HT) were used 40% and 100% bromined-P3HT to blend in active layer. Their Three materials blended under the different weight percent and the basic device configurations in this study was ITO / PEDOT : PSS / P3HT : Br-P3HT : PCBM / Al , efficiency was measured under AM 1.5G 100mW/cm2 illumination. When blended Br-P3HT(100%) in the active layer, VOC increased from 0.6V to 0.68V and the surface roughness makes short-circuit current and fill factor, increased make lower power conversion efficiency. When blended Br-P3HT(40%) into the active layer, not only can increase VOC to 0.66V, but influence the short-circuit current and the fill factor. The power conversion efficiency changed from 2.20% to 2.46%.
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吳家齊. "Investigation of the Miscibility, Crystallization, Melting, and Morphology of P3HT and P3HT/PCBM blend." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/92829392455993662553.
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Chun-YenYang and 楊俊彥. "Eutectic crystallization of P3HT/HMB binary system." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/42781553653355941561.
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碩士國立成功大學
材料科學及工程學系碩博士班
100
For the transportation of charge carrier with thin film of conjugated polymers, it is essential to have defect-free continuous crystalline domains widely extended as the channels. For the most studied conducting polymers P3HT, the assembly and crystal growth mechanisms have not been well understood, and only limited extent of crystallinity, less than 30%, has been reached. Therefore it is important to generate new understanding of low dimensional polymer physics for enhancing crystallinity, and optimizing crystal orientation and morphology. For discovered eutectic binary systems composed of conjugated polymers and small organic molecules, disparate crystallization sequences were unveiled via the change of composition. It is possible to design and construct hierarchical structures within thin film via eutectic system. While the component of small molecule crystallizes first, the following epitaxial crystallization of conjugated polymers was found able to form large scale of continuous edge-on crystalline lamellae as being guided by underneath crystalline substrate. Nevertheless, while lattice match is not available, the liquid crystalline phases were proposed to develop instead. The P3ATs represent a class of conjugated polymers widely used as the hole-transporting material in organic field-effect transistors (OFETs). The interested transportation properties were recognized strongly depends on the molecular parameters, and processing conditions. It is because these factors are all capable of causing the changes in two-dimensional molecular ordering in the thin film. The purpose of this research is to establish the phase diagram of eutectic binary systems of conjugated polymers, and explore the impact of crystallization route and epitaxial relationship to the crystal growth habit for enhancing thin film performance.
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Chen, Po-yu, and 陳柏佑. "P3HT/PCBM/PMMA blended polymer solar cell study." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/99636896502278923581.
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碩士明道大學
光電暨能源工程學系碩士班
98
In this study, the P3HT/PCBM active layer was used in an organic solar cell, and then we blended different ratio of the PMMA. A key factor of power efficiency was ratio of the PMMA. The measurement of I-V characteristic curve was performed, in order to calculate the power conversion efficiency of an organic solar cell. When the ratio of P3HT:PCBM:PMMA was 5:4.8:0.2, we could get the best performance power conversion efficiency of solar cell. The open circuit voltage (VOC) was 0.38 V and the short circuit current (JSC) was increased from 4.91 to 10.1(mA/cm2). Finally, the power efficiency is increased from 0.73% to 1.58%.
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陳猛飛. "Study of process variation on P3HT-Based OTFTs." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/85869978277581240961.
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碩士國立交通大學
電機學院微電子奈米科技產業專班
97
A procedure is studying and using the solution-process to fabricate P3HT-based organic thin film transistor. Using appropriated solvent and weight percentage is needed. And then the P3HT solution will be spun and deposited to be as active layer for organic electronic. P3HT organic material is to be classified to conjugated polymer. One of advantages is a property of self-organization and based on this structure to form a long chain. This long chain will be formed a lamella structure. If this lamella were packing closely, it would result a high regioregularity, which could obtain high mobility. Due to different process method, this lamella will be formed edge-on or face-on result. In my experiment, First of all, using chloroform to be a solvent with 0.1 weight percentages to fabricated OTFT can obtain better performance than xylene made, due to solubility and like dissolves like. Subsequently, we study the difference between regioregularity and molecular weight, two solutes were purchased from two different companies, dissolved them in the same solvent, chloroform. The result is that the difference of molecular weight is more importance than regioregularity. Moreover, fabricated by spin speed at 1500rpm and curing at 150℃ for 3 minutes can exhibit optimized result and in the meantime, observe that the oxygen concentration is less and less in the thin film analyzed by Auger electronic and ECSA surface elemental. Known a basic process procedure, there is a Schottky barrier between metal and organic material resulting less the current transport. However, S/D deposited with gold and an appropriated adhesion layer can reduce this barrier height, due to their closest work function and surface chemical property. In addition to previous results, to use surface treatment (HMDS) is a good idea to improve the packing and ordering for strong chain interaction and lead to exhibit high mobility and approximate to VG=0 of threshold voltage. In end of this thesis, we discuss about stability characteristics. Storage in the atmosphere, all of organic material will degrade as time goes by. This result is the same as P3HT polymer when it has been stored for one month. But the off current can be “healed” by annealing process at 180℃ for 30 minutes in furnace with N2 flow. Extra, low molecular weight comes to the same thing. Meanwhile, a device undergoing a serious process procedure can obtain a better performance, too. The on/off ratio is improved from 6x104 to 8~6x106; suspect that oxygen molecule can be driven off during annealing process. Unfortunately, the mobility is not to be improved and reduce down to 0.3x10-3 from 6x10-3 slightly and Vth is shifted to more negative, due to chain torsion. Last, constant voltage stress is applied to see how the drain current change. During stress, the drain increases with stress time going by when only drain electrode is applied at -60 voltages. There is no any gate current to be observed. We find out that the basic electrical result of the same device is changing after stress. A slight movement in off current, compared with just annealing one. So we suspect that the oxygen may diffuse into the film during stress.
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Huang, Tse-Kai, and 黃則凱. "Hybrid P3HT/TiO2 Nanorods Bulk Heterojunction Solar Cells." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/52034833220423155708.
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碩士國立臺灣大學
材料科學與工程學研究所
95
The investigations focus on hybrid materials photovoltaic properties of organic conjugated polymer and inorganic nano-semiconductor. First of all, we discuss how TiO2 nanorods support charge separation and charge transport in TiO2/P3HT hybrid solar cells. Therefore we tune the TiO2 doping concentration to optimize devices performance. Secondly, we focus on the topic of thermal treatment effect on devices performance. It is observed that devices performance could significantly enhance after high temperature annealing. Based on optical properties, XRD, and Time-of-Flight carrier mobility measurement system, we discover that after annealing both the crystallite size and carrier mobility increasing. Finally, we use synthesis method to change the length of TiO2 nanorods and investigate the length dependent effect on devices performance. We know that TiO2 inclusion supports both charge separation and transport, therefore we focus on different length of TiO2 nanorods effect on charge separation and transport properties. At the same doping concentration, the shorter TiO2 nanorods result in more surface area and contribute to more efficient charge separation; the otherwise the longer TiO2 nanorods could easily form continuous transport path to support efficient charge transport. Based on the balance of these two effects, we try to find the maximal performance of TiO2/P3HT hybrid solar cells.
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Jiang, Chin-Jung, and 江致榮. "Study on P3HT FET and active matrix circuit." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/49830524507630797119.
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碩士國立清華大學
電子工程研究所
94
Integrating polymer light-emitting diodes (LED) and polymer field-effect transistors (FET) on one substrate to fabricate 2T1C active-matrix array circuit by solution process can reduce the cost substantially. The polymer devices can be fabricated on various substrates, such as flexible substrate. Additionally, organic LEDs are regarded as the potential technology in display with advantages of high brightness, high contrast, and low operating voltage. We use P3HT as semiconductor, use SiO2 as insulator, and successfully fabricate FET with mobility of 10-2 (cm2/V-s) and on/off ratio of 104 on glass substrate. To increase reliability of P3HT FET, we use chromium as gate material. To lower leakage current, we design new mask. We also use different coating methods and O2 plasma treatment to enhance mobility. Eventually, we applied P3HT FETs to 1T1C active-matrix circuit and obtained successful operation of charging and discharge in this 1T1C circuit at 10Hz, 100Hz, 500Hz, and 1KHz. The fastest rise time is 0.3 (ms).
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Chang, Ching-Min, and 張景閔. "Research on P3HT/CdSe/TiO2 Composite Solar Cell." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/79218812049197965634.
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博士南台科技大學
機電科技研究所
99
This study presents the manufacturing processes and feasibility of multilayer structured P3HT/CdSe/TiO2 solar cell. The conception was to utilize the matching of energy band gap between the titanium dioxide (TiO2), cadmium selenium (CdSe), and organic dye P3HT to broaden the absorbable range of sunlight spectrum and produce the effective current in the solar cell. The studied items are: (I) Summarizing the suitable manufacturing parameters for each layer of thin film by the experimental results, (II) Analyzing the effect of target to substrate distance by sputtering on the thin film deposition process, (III) Analyzing the effect of substrate temperature and thickness of thin films to the type of crystallization, surface morphology, and photoelectric characteristics of TiO2 and CdSe, (IV) Analyzing the photoelectric properties of organic dye P3HT and aluminum thin films, (V) Discussing the feasibility of four kinds of structured solar cells. From literature reports, both CdSe and organic dye P3HT had the absorbable characteristics within the range of visible light; as if they and TiO2 were combined the solar cells would be achieved due to their match able energy band gaps. Based on this principle, four structured solar cells including P3HT/TiO2, CdSe/TiO2, P3HT/CdSe and P3HT/CdSe/TiO2 were designed, and then the suitable manufacturing parameters for each layer of the thin films by measuring and analyzing for the designed solar cells were investigated. By using different manufacturing parameters, sputtered thin films of TiO2, CdSe, and spraying on spun thin film of P3HT were fabricated. According to the experimental results, the TiO2 thin film with thickness of 500 nm deposited at target to substrate distance of 5 cm under 200 oC, had rougher surface, suitable spectrum absorbance (below 380 nm) and energy band gap. The CdSe thin film with thickness of 900 nm deposited at target to substrate distance of 3 cm under 25 oC had better absorption from visible light (below 730 nm) and smallest energy band gap. The P3HT thin film with thickness of 70 nm spun at room temperature had better flatness and absorption from visible light (450 nm-650 nm). All four types of structured solar cells had absorption ability in range of visible light, especially for the CdSe added thin films were more obvious, and the best absorption was found for P3HT/CdSe/TiO2. Moreover, all four types of structured solar cells generated Current-Voltage curves, the CdSe/TiO2 showed the better photoelectric conversion efficiency.
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Lin, Zong-Rong, and 林宗嶸. "Graphene Nanostructures for Organic P3HT Thin Film Transistors." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/86872776600847513736.
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碩士國立交通大學
照明與能源光電研究所
105
Technology has always come from human nature. In recent years, information terminal devices have become more convenient and easily portable to meet customers’ needs. This desire and request gradually stimulates the development of flexible electronics. Conventional electronic components use silicon wafers or glass as the substrate material and are fabricated using expensive lithography processes, while flexible electronics use either Spin-Coating or Ink- -jet Printing) and other process technology. Microelectronic components are manufactured on flexible substrates, which significantly reduce the cost of traditional semiconductor processes and make organic materials attract attention in recent years. Many manufacturers have also invested in research and development. Electronic products made of inorganic materials in the past are replaced by organic materials were many advantages, also developed many products. For example, electronic paper, flexible display, OTFT, and RFID tags. In the fabrication process of organic devices, solution based process were adopted in this study, which have advantages such as low cost and low process temperature. However, the electrical properties of organic thin film transistors(OTFT) are usually poor compare with thin-film transistor made of inorganic materials. The performance improvement on OTFT is therefore an important research issue and will be investigated in this thesis. This study utilized graphene nanostructures a mobility enhancer for organic thin film transistors. The loading of graphene plays a crucial role in transistor performance. In our research, when we hybrid 1wt% graphene nanostructures in P3HT. A ten-fold enhancement in device mobility(0.00626→0.0619 cm2/Vs) has been successfully achieved. The second is to employ graphene as barrier films layer covering the surface of OTFTs. The purpose is to isolate the gas molecules and water molecules in the environment in order to extend the operational life of the components. In the atmospheric environment, through the measurement of electrical components can be found organic thin-film transistor devices without a graphene film barrier have lost their transistor characteristics over a 10 days, and the use of graphene film as a barrier layer of the organic thin film transistor components in the life of 57 days to gradually lose the transistor characteristics. It can be found that adding a barrier layer of graphene film can effectively block the destruction of organic semiconductors by water and oxygen, increasing the component life of up to 47 days.
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Ji, Ya-Ting, and 紀雅婷. "Solar P3HT/TiO2 Photocatalytic Degradation of Azo-Dye Wastewater." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/71080379295785425243.
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碩士國立聯合大學
環境與安全衛生工程學系碩士班
103
Solar P3HT(Poly 3-hexylthiophene)/TiO2 photocatalytic degradation of azo dyes (MeO & AO7) wastewater was investigated in this study. P3HT(0.5%)/TiO2 and P3HT(1.0%)/TiO2 composites were prepared by novel shell-core method and partial shell-core method. The physical and chemical properties of P3HT/TiO2 composite nano-particles were characterized by Scanning Electron Microscope (SEM), X-ray Energy Dispersive Spectrometer (EDS), X-ray diffraction (XRD), and UV/VIS Diffuse Reflectance Spectroscopy (UV/VIS DRS). The spectrum of UV/VIS DRS showed that P3HT/TiO2 composites were much more responsive to visible light than TiO2. The higher the P3HT content, the more the absorption in the band of visible light. Moreover, the analysis of EDS confirmed that the molecule of P3HT with a desired content existed in the P3HT/TiO2 composite. Response surface methodology (RSM) with a 3*3 experimental design of Box-Behnken, ANOVA and a 3-1-1 model of artificial neural network (ANN) were applied to assess the effect of critical process parameters ([catalyst], P3HT content, O2 aeration rate) on treatment performance in terms of azo-dye molecular decomposition efficiency and abs@λmax reduction efficiency. Optimized reaction conditions were established as (1) P3HT/TiO2 (shell-core type) photocatalytic degradation of MeO dye wastewater: [catalyst]: 1.5 g/L, P3HT content: 0.5%, composites catalyst percentage: 25% and a reaction time of 120 min for reaching a 90% efficiency of abs@λmax(464 nm) reduction, ADMI removal and MeO molecular decomposition; (2) P3HT/TiO2 (partial shell-core type) photocatalytic degradation of MeO dye wastewater: [catalyst]: 1 g/L, P3HT content: 0.5%, a O2 aeration rate of 0.5 L/L/min and a reaction time of 60 min for reaching a 80% efficiency of abs@λmax(464 nm) reduction; (3) P3HT/TiO2 (Partial shell-core type) photocatalytic degradation of AO7 dye wastewater: [catalyst]: 1 g/L, P3HT content: 0.5%, a O2 aeration rate of 0.5 L/L/min and a reaction time of 60 min for reaching a 95% efficiency of abs@λmax(483 nm) reduction, ADMI removal, AO7 molecular decomposition. Moreover, it was found that the degradation efficiency of dye wastewater increased basically as the dosage of photocatalyst increased. An appropriate presence of P3HT content and O2 supply rate were beneficial to solar photocatalytic process. The dosage of photocatalyst was considered as the most weight parameter of azo-dye photocatalytic degradation on the basis of ANOVA and ANN model analysis. On the other hand, TiO2 were almost coated by P3HT in shell-core type P3HT/TiO2 photocatalyst, leading to a lower shift rate of electrons and a lower photocatalytic efficiency of dye wastewater than the partial shell-core type P3HT/TiO2 photocatalyst. It was evident that the AO7 molecule decomposition efficiency and abs@λmax(483 nm) reduction efficiency of dye wastewater increased 24.8% and 28.6%, respectively as partial shell-core type P3HT/TiO2 instead of shell-core type P3HT/TiO2 used in a photocatalytic reaction. Based on the results obtained in this study, the introduction P3HT onto the partial surface of TiO2 by partial shell-core method could extend successfully the visible light photoresponse range of TiO2 and increase free radicals formation, leading to effectively enhance TiO2 solar photoactivity. Also, a desired O2 aeration was reliable for solar photocatalytic process.
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Huang, Zih Ciao, and 黃子喬. "Studies on P3HT/PbS QD Bulk Heterojunction Solar Cell." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/72782023922527730338.
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碩士國立清華大學
化學工程學系
104
Bulk-heterojunction (BHJ) polymer solar cell (PSC) has attracted great attention because of its ease of fabrication, promising flexibility, and capability for large-scale and low-cost production. For common conjugated polymer Poly (3-hexylthiophene-2,5-diyl) (P3HT) : [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) system, the power conversion efficiency (PCE) has reached 5%. In order to achieve higher device performances, we replaced PC61BM with PbS quantum dot (QD) which possesses air stability, ease of synthesis, and low-cost fabrication. PbS QD has higher light absorption from the wavelength 200 nm to 400 nm than PC61BM, which is in complementary with P3HT that absorbs the light in long wavelength region 400 nm-600 nm. In this thesis, we dedicated to improve PCE of P3HT:PbS QD hybrid solar cell. We introduce the long-length (18 carbon length) oleic acid (designated as OA ligand) in the PbS QD synthesis procedure in order to stabilize the PbS QD. But the OA ligand is unfavorable for carrier transport, which results from long insulated alkyl, it is necessary to exchange long-length OA ligand to short-length ligand. There are two methods for exchanging the OA ligand of PbS QD. First, long ligand exchanges to short ligand after QD film formation, which is called post-treatment in this thesis and is a common method for ligand exchange. In this method, the carriers transport mobility are enhanced, which is resulted from the shorter distance between QD though some cracks in the film appear after the ligand exchange process. Second, in order to reduce the cracks in the post-treatment, we introduce short ligand into PbS QD solution for ligand exchange in advance, called pre-treatment in this thesis. This research then tried to find out the dispersion extents of PbS QD and P3HT by the pre-treatment. The long-length OA ligand of PbS QD exchange to short-length ligand 1-decanethiol (DT), 1-octanethiol (OT), 1-hexanethiol (HT) and 2-ethylhexanethiol (HET) in the pre-treatment. The OA ligand of PbS QD are designated as PbS-OA, and the PbS QD after the pre-treatment are designated as PbS-DT, PbS-OT, PbS-HT, and PbS-HET, respectively. Except for dispersing PbS QD by alkyl chain molecules, we also found that the short alkyl ligand PbS QD interacts well with the side-chain of P3HT. In the Atomic Force Microscope (AFM) topography and phase image, we found that the dispersion extent of P3HT and PbS QD increases when the ligand of PbS QD is exchanged in the pre-treatment, especially for the case exchanging by branched ligand (HET). Furthermore, we blend P3HT with both PbS-HT and PbS-HET together, the domain size of PbS QD is much smaller, the dispersion extent of P3HT and PbS QD is further improved, and a PCE of 3.95% is attained, which is the highest PCE in P3HT:PbS QD BHJ solar cell ever documented.
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Shu-ChienHsu and 許書倩. "Interfacial Modification of TiO2 Nanorod Array-P3HT Heterojunction Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/29104176153476913395.
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Wang, Chung-Chieh, and 王俊傑. "Study on Phthalocyanine and P3HT/Si Substrate Hybrid Solar Cells." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/8wb9cs.
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博士國立臺北科技大學
光電工程系研究所
97
The present paper reports on the photovoltaic properties of zinc phthalocyanine (ZnPc) films with various dopants, sandwiched between indium tin oxide (ITO) and n-type silicon (Si) substrates were investigated. For the ITO/p-ZnPc/n-Si sandwich structure solar cells, which ZnPc doped with I2 and without post-annealing, the measured parameters were the short-circuit current density (Jsc), the open-circuit voltage (Voc), the maximum output power (Pm), the fill factor (FF) and the efficiency (η), which had values of were 28.8 mA/cm2, 0.46 V, 5.55 mW/cm2, 0.42 and 5.55 %,. The DSSCs with 5 wt% ZnSe QDs exhibited optimum results. The short-circuit current density Jsc = 4.83 mA/c , the open-circuit voltage Voc = 0.44, the fill factor FF = 0.301, and the power conversion efficiencies η = 0.64%. By adding gold nanoparticles layer between TiO2 and dyes could promote short-circuit current density Jsc and reduce the open-circuit voltage Voc. Finally, =5.79 mA/cm2, Voc = 0.32, FF = 0.34 and η = 0.64 % were obtained. Solar cells are often covered with antireflective surfaces to enhance their performance. Porous silicon (PS) samples were prepared by DC electrochemical etching of p silicon wafers under different controlled voltage. The results indicate that the reflection of light emissions is related with etched voltage and time. We were fabricated, which has a reflectance below 8% over a broad band from 280 to 800nm. The solar cells were made of a porous silicon covered an organic layer to be a p-n junction. Finally, the best measured parameters of PV cells with P3HT/PS structure were the short-circuit current density Jsc = 36.8mA/cm2, the open-circuit voltage Voc = 0.34, FF = 0.225, and the efficiency η =2.81 %
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Chao, Hsuan, and 趙璿. "Charge transport and optoelectronic properties of MoS2/P3HT nanowires heterojunction." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3rk9th.
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碩士國立交通大學
電子物理系所
106
In this study, mechanical exfoliation method was used to generate few-layered molybdenum disulfide (MoS2) flakes. We transferred MoS2 flakes onto silicon substrates capped with 300-nm thick silicon dioxide layer. A standard electron-beam lithography with spin coating, thermal evaporation, and post annealing was employed to fabricate devices of MoS2/P3HT nanowires heterojunction field-effect transistors (FETs). Finally, we put those heterojunction FET devices in a probe station with illumination of laser light for measurements of electrical and optoelectronic properties at room temperatures. The FET devices of MoS2 demonstrates n-type behaviors while those of P3HT nanowires demonstrates p-type features. Both of them possess a good ohmic contact behavior with contact electrodes of Au. In addition, the heterojunctions of MoS2/P3HT nanowires show diode properties. The transfer characteristics (Ids-Vg curves) of the heterojunctions show either tunneling or recombination features, depending on the back gating voltage. Further, when the source-drain bias voltage on the MoS2/P3HT nanowires heterojunction is higher than 4 V, voltage dependent transport behaviors changes from direct to Fowler-Nordheim tunneling. A band structure model is proposed to explain the three different field-dependent electron transport manners. Finally, we investigate the photovoltaic and photo-detecting performances of the MoS2/P3HT nanowire heterojunctions under exposure of 633 or 405-nm wavelength laser. The power conversion efficiency (PCE) is larger when 633-nm laser is used for excitation. The PCEs of the heterojunction devices are tuned by the back gating voltage. The highest PCE of ~0.1 % is obtained and the magnitude is in line with those reported in the literatures. Under 633-nm laser exposure, the MoS2/P3HT nanowires heterojunction also shows a higher external quantum efficiency in comparison with the results with 405-nm light exposure. At a zero source-drain bias voltage, the heterojunction devices can work as a special photodetector, as well, with high sensitivities such as a reproducible and stable on-off ratio up to 1000.
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Chen, Dian. "Organic photovoltaics based on P3HT/PCBM: correlating efficiency and morphology." 2011. https://scholarworks.umass.edu/dissertations/AAI3482595.
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Controlling the morphology of thin films is key in optimizing the efficiency of polymer-based photovoltaic (PV) devices. The morphology and interfacial behavior of the multicomponent active layers confined between electrodes are strongly influenced by the preparation conditions. Results obtained in this work quantitatively show the photovoltaic device performance is strongly affected by the nanoscopic morphology, crystal orientation, composition distribution and the interdiffusion behavior of the photoactive layer. To better understand the physics of the photoactive layer in the organic photovoltaic devices, it is necessary to gain a quantitative understanding of the morphology and the manner in which it develops. A key element in the kinetics associated with the structure development is the interdiffusion of the components. To that end we used poly(3-hexylthiophene) (P3HT) / [6,6]-phenyl C61-butyric acid methyl ester (PCBM) bilayers as a model to investigate the interdiffusion of the components and its role in the development of the morphology. A detailed description of the diffusion behavior and the morphology developed from a layer of P3HT in contact with a layer of PCBM during thermal annealing is given. Amorphous P3HT and PCBM are shown to be highly miscible and PCBM can penetrate into the P3HT layer through the P3HT amorphous region and form the bulk heterojunction structure within a few second of annealing at 150°C. The results indicated that one phase is a pure P3HT crystal domain and the other phase is the mixture of amorphous P3HT and PCBM, which is not consistent with a phase separation of the components by a spinodal decomposition mechanism. We put forth an alternative mechanism, namely a competitive crystallization/diffusion argument, to describe the origin of the morphology. These findings provide new insights and guidance in the generation of active layers in organic photovoltaics that are crucial in enhancing the device performance. Textured organic solar cells were also studied, providing another route to fabricate higher performance devices.
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Tang, Yu-Shiuan, and 唐鈺軒. "Theoretical Study on the Surface Modified TiO2:P3HT Hybrid solar Cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/90435609186809675439.
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碩士國立臺灣大學
化學工程學研究所
100
In this thesis, we develop a theoretical model for modeling the current-voltage characteristics of surface modified TiO2/P3HT hybrid solar cells. This model considers the adsorption of photons, the excitation and transport of excitons, the formation of polaron, and its dissociation to free charge carriers. The transport of free charge carriers is governed by the poisson and continuity equations. We found that the surface modifier enhances the efficiency of polaron dissociation. The efficient polaron dissociation can result in high fill factor and high open circuit voltage. However, compared with the organic polymer solar cells, there is a significant loss of excitons before they can be converted to poalrons in surface modified TiO2/P3HT solar cell. This is the main reason for the lowered efficiency of the surface modified TiO2/P3HT solar cells.
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Lee, Yi-Jung, and 李依蓉. "Experimental study on thermoelectric properties of P3HT nanowires and thin films." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/47796325548695024117.
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碩士國立交通大學
應用化學系碩博士班
102
In recent years, thermoelectric energy has become more popular due to the fact that we are constantly searching for new solutions to solve the looming energy crisis. To determine the heat conversion efficiency of a material, one must measure its figure of merit (ZT value). In general, a higher ZT value would mean greater efficiency of turning heat into electricity. Electrical conductivity, thermal conductivity and Seebeck coefficient are much related to ZT value. Among various thermoelectric materials, semiconductors are the most popular materials that are constantly studied due to their better ZT values. Recently, the conducting polymer, Poly(3-hexylthiophene) (P3HT), has been extensively studied because of its unique thermal and electrical properties. The band gap of P3HT is about 1.9 eV, which is in the same the band gap range of typical semiconductors. By making the P3HT into nanowires, we expects to lower the thermal conductivity of the nanowires due to the reduced dimensionality and to improve their ZT values. We successfully determined an electrical conductivity of 3.3x10-7 1/ohm from single P3HT nanowires. The value of the electrical conductivity remained stable even after wires were exposed in ambient for weeks. In addition, we fabricated “T-type” devices by using PECVD, E-beam lithography, E-gun evaporation and wet-etch to measure the thermal conductivity of single P3HT nanowires. We extracted a thermal conductivity of 0.0552 (W/mK) from a single P3HT nanowire.
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Shih, Min-Chuan, and 施敏權. "Scanning Tunneling Microscopy Investigation of Interfacial Properties between P3HT and PCBM." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/89314475132219591667.
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碩士國立中山大學
物理學系研究所
99
The electronic structures at the hetero interface of Poly(3-hexylthiophene): methanofullerene (P3HT:PCBM) have a great improvement on the solar cell efficiency due to the formation of bicontinuous nanoscaled phase separation which will enhance charge separation and carrier transport. In the present work, cross-sectional scanning tunneling microscopy and scanning tunneling spectroscopy measurements are utilized to obtain the in-situ atomic-scale band structure across the interface between P3HT and PCBM directly. The distribution of PCBM volume concentration of organic films was also analyzed and discussed in the work.
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Yi-HaoChang and 張鎰浩. "Light Propagation and Photovoltaic Performance in P3HT/Titania Nanofiber Heterojunction Devices." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/33103924561655273188.
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碩士國立成功大學
材料科學及工程學系碩博士班
98
Randomly deposited titania nanofibers from the polymer-assisted electrospinning fabrications were utilized as the light propagation matrix and the electron transporter in the poly(3-hexyl thiophene) (P3HT)/TiO2 heterojunction solar cells. Taking the advantages of light scattering effects occurred within the titania nanofiber scaffolds, the light path lengths of the incident irradiation were significantly increased as functions of fiber diameters and fiber deposition thicknesses. Assembles of the P3HT/TiO2 heterojunction photovoltaic devices were first investigated in terms of the extra fiber compression, the P3HT/TiO2 ratios, the preferred scattering bands, and more. Photovoltaic outcomes were then carefully examined and analyzed. For the light scattering and propagation effect, it was found that the titania nanofiber with the average diameter of 290nm had the preferred scattering band mostly overlapped with the P3HT absorption wavelength. As a result, this particular sample revealed the best performance in comparison with other devices with different titania fiber diameters. Moreover, the thickening of titania nanofiber deposition layers was incorporated with the increase of energy conversion. Experimental results showed that the current densities and the fill factors were both linearly increased with the cell thicknesses, suggesting the energy accumulation from the light scattering effects. These observations indicated the light propagation and the improvement of energy conversion efficiencies were successfully demonstrated in the solid-state heterojunction solar cells constructed by electrospun titania nanofibers and conducting polymers.
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Chang, Chia-Hao. "Study of carrier mobility in P3HT/TiO2 nanocrystals hybrid bulkheterojunction structures." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1407200815092500.
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CHIU, PEI-SHAN, and 邱沛珊. "Solar Photocatalytic Degradation Of Phenols Wastewater With Ag/P3HT@TiO2 Nanocatalysts." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/58842591209223215465.
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碩士國立聯合大學
環境與安全衛生工程學系碩士班
105
Solar Ag/P3HT(Poly 3-hexylthiophene)@TiO2 photocatalytic degradation of phenols (phenol & 4-CP) wastewater was investigated in this study. Nano-photocatalysts Ag/P3HT@TiO2 composite was prepared by a novel partial shell-core method and photo-reduction method. The physical and chemical properties of Ag/P3HT@TiO2 nano-particles were characterized by Flame Atomic Absorption Spectrometry (AA), Scanning Electron Microscope (SEM), X-ray Energy Dispersive Spectrometer (EDS), X-ray diffraction (XRD), and UV/VIS Diffuse Reflectance Spectroscopy (UV/VIS DRS). The results showed that a 60-80% of the noble metal (Ag0) was deposited on the surface of TiO2 photocatalyst and the silver can be deposited onto the TiO2 surface in 15 to 30 minutes. The images of SEM showed the particle size of Ag/P3HT@TiO2 and TiO2 nano-particles with a similar range of 12-20 nm. The analysis of EDS confirmed that the molecule of P3HT and Ag with a desired content existed in the Ag/P3HT@TiO2 composite. Moreover, the results of XRD indicated the crystal pattern of TiO2 still presented mainly anatase form in Ag/P3HT@TiO2 composites. The spectrum of UV/VIS DRS showed that Ag/P3HT@TiO2 composites were much more responsive to visible light than TiO2. The higher the P3HT and Ag content, the more the absorption in the band of visible light. Using composition of the optimal Ag(0.05%~0.15%)/P3HT(0.5%)@TiO2 nanocatalysts, with catalysts of 0.5 g/L, a light irradiation of 500 W/m2 and a reaction time of 120 min could reach 79%~83% and 90%~92% efficiency of the abs@λmax reduction and 90%~93% and 99% efficiency of degradation, for phenol and 4-CP wastewater, respectively. Also the abs@λmax reduction efficiency of phenols wastewater could increase 9.15% (120 min) and 14.63% (90 min) for phenol and 4-CP wastewater, respectively as O2 aeration rate increased from 0 L/L/min to 0.5 L/L/min, which could contribute the overall reaction. If the photocatalytic experiment is carried out in the absence of oxygen (aeration N2) in the wastewater, the electrons can not react with enough oxygen to reduce the generation of superoxide radical, resulting in the organic pollutants in the wastewater can not be completely decomposed, so the appropriate provision of dissolved oxygen in the wastewater to aid the photocatalytic oxidation reaction. Moreover, the abs@λmax reduction rate efficiency of phenols wastewater could increase 3.46 and 4.49 times for phenol and 4-CP wastewater, respectively as light irradiation increased from 250 to 750 W/m2; the abs@λmax reduction efficiency of phenols wastewater could increase 17.05% and 7.2% for phenol and 4-CP, respectively as wastewater temperature increased from 15 °C to 25 °C, when the wastewater temperature increased to 35 °C, the degradation efficiency of wastewater promoted slowly. Based on the results, increasing the light irradiation can accelerate the generation of electrons and holes, thus accelerating the formation rate of hydroxyl radicals, and promoting the oxidation reaction. Appropriate increasing wastewater temperature could contribute to increase the frequency of collision between molecules and molecules, which is beneficial to improve the photocatalytic efficiency. However, the wastewater temperature effect is slowed down under fixed light intensity. With the assistance of Fresnel lens in the solar photocatalytic degradation of phenols wastewater could greatly enhance the degradation rate of phenols wastewater. The feasibility of photocatalytic technology using the composite nanocatalysts synthesized in this study was obvious. On the other hand, the photocatalytic efficiency of using solarlight as the light source was promoted, which can significantly save the operation cost . Based on the results obtained in this study, using the noble metal-Ag and P3HT (Poly 3-hexylthiophene) to modify the TiO2, can improve the TiO2 can only absorb ultraviolet light and electron-hole pairs of easy to re-combination. In this study, the partial shell-core type Ag/P3HT@TiO2 composite nanocatalysts can promote the photocatalytic degradation the difficult to decompose organic wastewater such as phenols wastewater and practical application of the increase, by the assistance of Fresnel lens in the actual solar light source. Keywords：partial shell-core type P3HT/TiO2, photocatalysis, phenols wastewater, phenol, 4-chlorophenol, Fresnel lens
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Hsu, Fang-Ying, and 徐芳瑩. "Thin Films based on P3HT and Emeraldicene Derivatives for Electronic Devices." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/89743917844484321278.
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碩士國立臺灣大學
高分子科學與工程學研究所
102
Several polycyclic heteroaromatic hydrocarbons with planar structures such as emeraldicene (EMD) and its derivatives 2EH-EMD, 2Br-2EH-EMD, and an aromatic compound with non-planar structure such as 2Th-An were synthesized and characterized. These four compounds were respectively used as additives to blend into P3HT with different weight ratios (1 wt%, 2 wt%, 5 wt%, 25 wt%, and 50 wt%) for organic thin film transistors (OTFTs). After spin-coating the thin films, we used the solvent treatment to enhance the ordered packing of the polymer chains. Photophysical properties were determined by UV-visible spectroscopy and photoluminescence. There were no changes on the absorption peak and the emission peak of P3HT after blending the small molecules into it. OM results indicate that for P3HT/ 2Th-An (25 wt%), P3HT/ 2Th-An (50 wt%) and all of P3HT/ 2EH-EMD samples, the domain sizes were larger than that in P3HT. For the P3HT/ EMD and P3HT/ 2Br-2EH-EMD samples, the aggregation of small molecules was observed. A series of organic thin film transistors based on the respective blends of P3HT and small molecules were fabricated. Electrical properties could be measured only for the P3HT/ 2EH-EMD and P3HT/ 2Th-An samples. The ranges of mobilities were about 10-4 to 10-2 cm2V-1s-1. The highest mobility (3.6×10-2 cm2V-1s-1), on/off ratio (1.8), and threshold voltage (-10.1 V) were observed for the P3HT/ 2Th-An (25 wt%) based organic thin film transistor.