Дисертації з теми "Organic Solar Cells, Conjugated Polymers, Organic Electronics"
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DANESH, CAMERON DEAN. "SURFACTANT FORMULATIONS FOR WATER-BASED PROCESSING OF A POLYTHIOPHENE DERIVATIVE." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1058.
Повний текст джерелаKovacik, Peter. "Vacuum deposition of organic molecules for photovoltaic applications." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:98461a90-5ae3-4ae3-9245-0f825adafa72.
Повний текст джерелаYahya, Wan Zaireen Nisa. "Synthèse et caractérisation des oligomères et polymères Ä-conjugués nanostructurés pour applications en photovoltaïque." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENV074/document.
Повний текст джерелаOrganic photovoltaic (OPV) cells have been a subject of increasing interest during the last decade as they are promising candidates for low cost renewable energy production. In order to obtain reasonably high performance organic solar cells, development of efficient light absorbing materials are of primary focus in the OPV field. In this context, the present work is focused on the design and development of new electron donor materials (oligomers and polymers) as light absorbing materials based on “Donor-Acceptor” approach alternating electron donating group and electron withdrawing group. Three main families of electron donating group are studied: oligothiophenes, fluorene and indacenodithiophene. Fluorenone unit is the principal electron withdrawing group studied and a direct comparison with the system based on benzothiadiazole unit as electron withdrawing unit is also provided. Three main synthetic methods were employed: oxidative polymerization mediated by Iron (III) chloride and Palladium cross-coupling reactions according to Suzuki coupling or Stille coupling conditions. Spectroscopic studies on absorption and photoluminescence have demonstrated the presence of characteristic charge transfer complex in all the studied D-A oligomers and polymers allowing the extension of the absorption spectrum. The D-A oligomers and polymers have shown an overall low optical band gap of 1.6-2 eV with absorption spectra up to 600 to 800 nm. The nature of the charge transfer complex transitions bands were found to be depending on the strength of the electron donating unit and the electron withdrawing unit. Furthermore molecular packing in solution and in solid state has also demonstrated to contribute to extension of absorption spectrum. The HOMO and LUMO energy levels of the oligomers and polymers were determined by electrochemical measurements. Fluorene-based polymers have shown low lying HOMO energy levels, and these polymers demonstrate high open circuit voltage (Voc) in photovoltaic cell when combined with fullerenes derivatives PCBM with Voc values close to 0.9 V. The oligomers and polymers tested in photovoltaic devices have shown promising results with the highest power conversion efficiency obtained of 2.1 % when combined with fullerenes PCBMC70. These results were obtained after only limited numbers of device optimizations such as the active materials ratios and thermal annealing. Therefore further optimization of devices may exhibit higher power conversion efficiencies
Cui, Chaohua. "Conjugated polymer and small-molecule donor materials for organic solar cells." HKBU Institutional Repository, 2014. https://repository.hkbu.edu.hk/etd_oa/37.
Повний текст джерелаDaoud, Walid. "Synthesis of conjugated polymers and their use in photovoltaic cells." Thesis, University of Sheffield, 2002. http://etheses.whiterose.ac.uk/14469/.
Повний текст джерелаZhan, Hongmei. "Synthesis, characterization and optoelectronic applications of new conjugated organic and organometallic polymers." HKBU Institutional Repository, 2011. http://repository.hkbu.edu.hk/etd_ra/1240.
Повний текст джерелаXu, Zongxiang, and 许宗祥. "Organic thin film transistors and solar cells fabricated with [pi]-conjugated polymers and macrocyclic materials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42182554.
Повний текст джерелаXu, Zongxiang. "Organic thin film transistors and solar cells fabricated with [pi]-conjugated polymers and macrocyclic materials." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42182554.
Повний текст джерелаMori, Daisuke. "Development of Polymer Blend Solar Cells Composed of Conjugated Donor and Acceptor Polymers." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199331.
Повний текст джерелаAndré, Johansson. "A photodegradation study of conjugated polymers for organic solar cells by absorption spectroscopy and atomic force microscopy." Thesis, Karlstads universitet, Institutionen för ingenjörsvetenskap och fysik (from 2013), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-84049.
Повний текст джерелаEffekten av simulerad solljusexponering i omgivande luft på tunna filmer gjorda av en elektronaccepterande polymer poly{[N,N'-bis(2-octyldodecyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (N2200), en elektrondonerande polymer Poly[[2,3-bis(3-octyloxyphenyl)-5,8-quinoxalinediyl]-2,5-thiophenediyl] (TQ1) och deras blandningar, har undersökts genom ultraviolett-synlig-spektroskopi (UV-vis-spektroskopi) och atomkraftsmikroskopi (AFM). Genom lösningar av TQ1, N2200 och blandningar, har det linjära förhållandet i Beer Lamberts lag för absorptionsspektroskopi verifierats. De mätta UV-vis-spektrumen visar att tunna TQ1-filmer är känsligare mot degradering genom simulerat solljus än tunna N2200-filmer. De visar också att den N2200-rika blandningen med ett volymförhållande av 1:2 (TQ1:N2200) var mindre känslig för degradering av simulerat solljus än blandningar med volymförhållandet 1:1 och 2:1. AFM-bilderna visade en förändring i råhet mellan degraderade och icke-degraderade filmer, där TQ1-, 1:1-, och 1:2-filmerna fick en lägre ytråhet efter 45 timmar av degradering, och N2200- och 2:1-filmera fick en högre ytråhet.
Huang, Chun. "Perylene diimide-based materials for organic electronics and optical limiting applications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42755.
Повний текст джерелаThesis advisor has approved the addition of errata to this item. Corrections were made to pages 95, 98 and 101.
Dal, Zilio Simone. "Innovative solution in organic photovoltaic devices." Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426627.
Повний текст джерелаIl problema energetico sta destando negli ultimi anni sempre maggior interesse e preoccupazione, per il ridursi delle risorse fossili e dal conseguente acuirsi dei problemi d’inquinamento derivanti dal loro quasi esclusivo utilizzo per la produzione di energia elettrica. Non è sorprendente quindi che dal mondo della ricerca un grande sforzo sia dedicato allo sviluppo della tecnologia fotovoltaica. Attualmente, il silicio possiede una posizione centrale nel panorama delle celle fotovoltaiche: l’elevato costo di questo tipo di tecnologia, derivato dall’alto costo del materiale e dei processi fabbricativi, ha incoraggiato lo sviluppo di soluzioni alternative che si basino su materiali innovativi. Tra queste, grande risalto è stato dato negli ultimi anni alle cosiddette "organic solar cell", basate sull’impiego di semiconduttori organici. Il loro vantaggio risiede nel fatto che questi possono essere depositati, su larghe aree e a costi molto ridotti, in fase liquida, utilizzando quindi metodi tipici dell’industria della stampa nel campo del fotovoltaico ed eliminando così alti costi di materiale e di processo tipici dell’industria a semiconduttore inorganico. L’impiego di film sottili e conseguentemente di poco materiale, contribuisce a rendere il fotovoltaico organico uno dei più quotati candidati per lo sviluppo di una tecnologia solare a basso costo. Una tipologia di celle solari organiche utilizza come materiali foto attivi i polimeri coniugati; evidenti progressi sono stati compiuti, col raggiungimento di efficienze ragguardevoli, dell’ordine del 4-5%. Purtroppo però, questo non è ancora sufficiente perché la tecnologia possa essere trasferita su scala industriale. Molti sforzi si stanno facendo nell’ambito della ricerca per migliorare l’efficienza di queste celle. Sullo sviluppo e l’impiego di soluzioni alternative e innovative applicabili al campo del fotovoltaico organico, e in particolare polimerico, è concentrata la nostra attività di ricerca. Due percorsi in particolare sono stati investigati, basate sull’impiego di un nuovo sistema per l’intrappolamento in cavità della luce e sull’impiego delle nanotecnologie fabbricative.
Guarracino, Paola. "Photophysical processes and molecular ordering in organic materials for third generation photovoltaics studied by EPR spectroscopy." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3424935.
Повний текст джерелаIl consumo mondiale di energia ha un tasso medio di crescita del 2.1 % all’anno, trainato dalla crescita economica di molti Paesi asiatici, dell’Europa e del Canada. Il conseguente depauperamento delle risorse di combustibili fossili e il più stringente bisogno di proteggere l’ambiente stanno facendo della sfida delle energie rinnovabili una delle più urgenti sfide che l’umanità deve affrontare. L’energia solare è tra i migliori candidati a svolgere il ruolo di punta nella rivoluzione energetica, essendo una fonte di energia pulita, infinita e ben distribuita nel pianeta. Per questo motivo le tecnologie fotovoltaiche per la produzione di energia elettrica stanno acquistando crescente popolarità. Sebbene le celle solari a base di Silicio dominino il mercato del fotovoltaico, materiali organici e ibridi sono fonte di crescente interesse grazie alle loro peculiari proprietà, come la flessibilità, la leggerezza e la trasparenza, il basso costo, che ci si aspetta possano fare la differenza nell’affermazione del fotovoltaico. Fino ad ora questi materiali non hanno superato il rendimento dei materiali convenzionali a base di Silicio, stimolando la ricerca scientifica verso lo sviluppo di nuovi materiali e lo studio dei meccanismi fotofisici che governano il comportamento fotovoltaico dei semiconduttori organici e ibridi. In questa tesi, una serie di nuovi materiali fotoattivi, organici e ibridi, è stata studiata utilizzando la spettroscopia di Risonanza Paramagnetica Elettronica (EPR). Tale tecnica, combinata con la fotoeccitazione, permette di caratterizzare i processi fotoindotti che portano alla formazione di stati paramagnetici come radicali e stati di tripletto. Come mostrato nella tesi, la tecnica EPR può essere anche utilizzata per ottenere informazioni circa l’ordine molecolare nei materiali, che è noto essere strettamente collegato alle loro proprietà di trasporto di carica. I polimeri coniugati sono noti per le loro proprietà di semiconduttori e le loro miscele con derivati fullereneci - forti electron-accettori - sono tra i sistemi fotovoltaici organici più efficienti. Copolimeri alternanti composti da unità elettron-accettrici e donatrici sono stati introdotti per aumentare l’efficienza di assorbimento dello spettro solare. Rispetto ai classici omopolimeri, questi mostrano solitamente una minore cristallinità dei film depositati. Pertanto, tecniche diffrattometriche si rivelano spesso inadeguate per caratterizzarne l’ordine molecolare. In questa tesi l’EPR viene utilizzato per analizzare l’ordine orientazionale in due polimeri rappresentativi di questa classe, mostrando che un grado consistente di orientazione preferenziale è presente nei film ottenuti con due diverse tecniche di deposizione. Materiali fullerene-free per le celle solari polimeriche sono stati recentemente introdotti per superare alcuni degli svantaggi degli accettori fullerenici, come il limitato assorbimento della luce solare e la difficoltà nel regolare il bandgap e le proprietà elettroniche. In questo conteso, abbiamo studiato due blend costituiti da polimeri elettron-accettori e donatori al fine di investigarne le proprietà e di compararle a quelle dei convenzionali blend di polimeri donatori con derivati fullerenici, dimostrando che essi eliminano la ricombinazione di cariche a formare stati di tripletto, meccanismo noto come fonte di perdita di efficienza nei materiali contenti fullereni. Inoltre, i film polimerici mostrano un elevato grado di ordine orientazionale e un’efficiente interazione tra le fasi di donatore e di accettore che li rendono promettenti alternative ai blend di polimero e fullerene. Un nanoibrido composto da grafene ossido ridotto e molecole di trifenilammina legati covalentemente, è stato studiato come potenziale colorante per la titania in celle solari sensibilizzate a colorante, capace di migliorare la conducibilità e la stabilità del sistema. L’EPR ha mostrato che un efficiente trasferimento elettronico fotoindotto avviene tra l’ibrido e il semiconduttore, aprendo la strada all’applicazione di una nuova classe di coloranti. Infine, la fotoattività di un materiale supramolecolare, un gel composto da piccole molecole di donatore e accettore che autoassemblano, è stata studiata. In questo caso l’EPR ha permesso di verificare un efficiente trasporto di carica attraverso le strutture supramolecolari, suggerendo interessanti proprietà semiconduttive del materiale. I risultati di questa tesi dimostrano la rilevanza dell’EPR per l’indagine su aspetti funzionali e morfologici di materiali fotovoltaici e forniscono una caratterizzazione della fotofisica di nuovi sistemi che potrebbero essere ulteriormente esplorati per apportare progressi sostanziali nel campo del fotovoltaico organico e ibrido.
Nagyová, Veronika. "Příprava a studium optoelektrických vlastností tenkých vrstev pro organickou fotoniku." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2013. http://www.nusl.cz/ntk/nusl-216944.
Повний текст джерелаSantos, Marcelo Alves dos. "Estudo atomístico da formação de interfaces orgânico-inorgânico: Tiofenos sobre óxido de titânio." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-02062008-132541/.
Повний текст джерелаIn the study of organic-inorganic hybrid systems, the use of materials such as conjugated polymers and transition metal oxides has attracted great interest. In particular, it is worth mentioning systems composed by thiophenes and titanium oxide, which have an important application in solar cells. For a better understand- ing of the interaction between these systems, it is necessary to know the polymer organization over the inorganic substrate. Therefore, we investigated in this work the formation of the interface between thiophene oligomers and the (101) surface of TiO2-anatase by means of a multi-formalism approach, which includes classical molecular dynamics simulations, and a combination of ¯rst principles calculations based on Hartree-Fock and Density Functional Theory (DFT) for structural and electronic properties. The simulation of deposition of thiophene oligomers on TiO2, which demands systems with thousands of atoms, was performed by classical molecular dynamics. As a prerequisite for the classical calculation for these systems, we performed a re-parameterization of the Universal force ¯eld for the oligomers, whose structures are not well described by standard force ¯elds, and for the TiO2 bulk and surface. We observed the formation of disordered and dense quaterthiophene ¯lms, with presence of a majority of molecules oriented almost perpendicularly to the surface plane. In the ¯rst interfacial layer we ¯nd also molecules oriented parallel to the sub- strate, which increases the contact between the organic and the inorganic systems. The deposition of isolated quaterthiophene and sexithiophene oligomers resulted in molecules disposed parallel to the surface and aligned along directions of periodicity of the surface atoms. We therefore studied the electronic properties of a system composed of poly- thiophene on TiO2, with the polymer parallel to the surface and oriented along a preferential direction, by means of DFT formalism. Although DFT treatments present known problems in the de¯nition of the energy gap, even of more relevance in our case of hybrid systems, the results for the occupied states revealed a sizeable displacement of the top of the valence band of one system with respect to the other. The misalignment will prevent the passage of a hole from the polymer to the oxide, providing in this way the necessary condition for the use of this type of system in solar cells. It was also seen electronic coupling between sulfur atoms from polythio- phene, and oxygen atoms from TiO2 through the presence of a state associated with an electronic density extended from the polymer to the surface. Our results thus indicate there is good electronic coupling between the (101) surface of TiO2-anatase and polythiophenes.
Heinrichová, Patricie. "Fotogenerace náboje v organických polovodičích." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-233406.
Повний текст джерелаKRAFT, THOMAS M. "DEVELOPMENT OF CONJUGATED COPOLYMERS FOR CARBON NANOTUBE-BASED SOLAR CELLS." Thesis, 2011. http://hdl.handle.net/1974/6315.
Повний текст джерелаThesis (Master, Chemistry) -- Queen's University, 2011-02-13 22:09:00.464
Kanimozhi, K. Catherine. "Rational Design of Diketopyrrolopyrrole-Based Conjugated Polymers for Ambipolar Charge Transport." Thesis, 2013. http://etd.iisc.ernet.in/2005/3389.
Повний текст джерелаLee, Kwang Jik. "Investigation of the photo-induced charge transfer in organic semiconductors via single molecule spectroscopy techniques." 2009. http://hdl.handle.net/2152/18642.
Повний текст джерелаtext
Hou, Chao-Jiun, and 侯朝竣. "Theoretical Studies of the Electronic and Optical properties of the Carbazole-Based Conjugated Polymers for Organic Solar Cell." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/93184853267941791795.
Повний текст джерела淡江大學
化學學系碩士班
97
Recently years, carbazole’s derivatives has been used in photoelectric material generally,and it’s absorption spectrum with solar spectral match. so using in solar cell material will have well absorption coefficient, several alternating polymeric structures have been investigated to carbazole’s derivatives for solar cell applications. This thesis are design the carbazole-based conjugated polymers and uses theoretical and computational methods DFT/B3LYP and basis set 6-31G* to optimize the derivatives structure than uses the TD/B3LYP/6-31G* and ZINDO to calculated the energy level, so we will get three different energy gap value, Eg(DFT)、Eg(TD)and Eg(ZINDO) , than we will get the oligomer n=1~4 energy gap value to find the linear equations, and use the extrapolation method to get the n=∞ energy gap, the Eg(TD)method is most close the experimental value. And we calculated the five oligomer with TD/B3LYP/3-21G to get absorption spectrum, and we will find three kind of oligomer have visible light absorption and two kind of oligomer have near IR absorption. Finally, we use HF/3-21G to calculate excited state structure and TD/B3LYP/3-21G to calculate emission spectrum, and the emission wavelength are between visible light range, so we can speculation the material may be a good photoelectric material. This investigate to provide a good method to design the solar cell material and design three kind of material, For feature it’s will be a good direct to design solar cell material.
Chen, Ting-Chih, and 陳亭芝. "Synthesis of Cross-Conjugated and Low Band-Gap Polymers and Their Applications in Organic Solar Cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/41644673702408432302.
Повний текст джерела國立交通大學
應用化學研究所
98
In recent years, polymer solar cells (PSCs) have been attracting considerable attention for many advantages, such as low cost, light weight, easy fabrication and their potential application in large area flexible devices. Since the discovery of the photovoltaic effect in bulk heterojunction (BHJ) devices, the considerable publications in PSCs have been reported. PSCs based on the concept of bulk heterojunction (BHJ) configuration where an active layer comprises of a p-type donor (conjugated polymer) and an n-type acceptor (fullerene derivative) materials, represents the most useful strategy to maximize the internal donor-acceptor interface area allowing for efficient charge separation. The goal of this research is to design and synthesize a series of new p-type conjugated polymers to achieve highly efficient BHJ solar cells. Six new cross-conjugated and low bad-gap copolymers have been synthesized and characterized. These of three-component donor-acceptor random copolymers are symbolized as (thiophene donor)m-(thiophene acceptor)n. The PCSTBT series are prepared by Stille coupling polymerization of 2,5-bis(trimethylstannyl)thiophene D1 with 1,4-dibromo-2,5-{bis(4-[N,N-(dioctylamino)styryl])}-benzene) D2 and4,7-dibromo-1,2,3-benzothiadiazole A1, while PCSTDPP series are prepared by Stille coupling polymerization of 2,5-bis(trimethylstannyl)thiophene D1 with1,4-dibromo-2,5-{bis(4-[N,N-(dioctylamino)styryl])}-benzene) D2 and3,6-di(2-bromothien-5-yl)-2,5-dioctylpyrrolo[3,4-c]pyrrole-1,4-dione A2. Thesynthesized copolymers are soluble in common organic solvents and possess good thermal stability. The UV-vis absorption spectra of these copolymers contain an intramolecular charge transfer (ICT) transition band, which lead to an absorption extending into near-infrared region and optical band gaps ranging from 1.36 eV to 1.75 eV. Polymer solar cells of a BHJ were fabricated with the structure of ITO/PEDOT:PSS/Copolymer:PCBM(1:2, w/w)/Ca/Al. The PCE were 0.10 % (PCSTBT25), 0.18 % (PCSTBT50), 0.32 % (PCSTBT75), 0.37 % (PCSTDPP25), 0.54 % (PCSTDPP50), 0.62 % (PCSTDPP75). The higher PCE for PCSTDPP75 copolymer solar cell is attributed to the low band gap of this copolymer compared to others, which increases the numbers of photogenerated excitons and corresponding photocurrent of device. Although their PCE is still relatively low, further improvement on device performance can be achieved through morphology control by thermal annealing and chemical annealing, and carefully device engineering.
Lo, An-Lun, and 羅安倫. "The investigation of low band-gap conjugated polymers and nickel oxide hole transport layers in organic solar cells." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/24263209209059093918.
Повний текст джерела國立臺灣大學
光電工程學研究所
101
The performance of bulk heterjuction (BHJ) solar cells based on low band-gap conjugated polymers and nickel oxide hole transport layers are studied in this thesis. In the first topic of this thesis, the devices of PCDTBT mixed with PC71BM as active layer materials are investigated. By decreasing the thickness of the active layer, the short circuit current density (Jsc) and power conversion efficiency (PCE) are enhanced. Comparing the devices with calcium, lithium fluoride and bathocuproine (BCP) as cathode buffer layers before the deposition of Al electrodes, Jsc of the devices with LiF and BCP buffer layers is higher and PCE of the devices with BCP buffer layers is the highest. The PCE of the device is 4.19%. To control the morphology of the active layer, 1,6-diiodohexane(DIH) is used as an additive, which results in increased PCE to 4.57%. In the second topic, we investigate the device of P3HT: PC61BM based organic solar cells using nickel oxide (NiOx) as the hole transport layers. Via x-ray and ultraviolet photoemission spectroscopy (UPS and XPS), the effects of post-treatment applied to NiOx is investigated. UV Ozone treatment on NiOx results in more metal cation vacancies which contribute to hole transport efficiency. The work function then increases from 4.8 eV to 5.1 eV. The device with ten minutes UV Ozone treatment of the NiOx has maximum fill factor (FF) and PCE. The devices with PEDOT:PSS and the devices with NiOx have similar PCE and Voc , but the former has higher FF and slightly lower Jsc. Additionally, the stability of the devices with NiOx is better than the devices with PEDOT:PSS. In the third topic, we study the device of PBDTTT-C-T: PC71BM as the active layer materials. To achieve the optimized PCE, the active layer parameters such as thickness and concentration are tuned, resulting in the best PCE of 6.10%. Due to the broadened absorption wavelength range and deeper highest occupied molecular orbital (HOMO) of PBDTTT-C-T in comparison with P3HT, Jsc and Voc are higher of the device with PBDTTT-C-T. Then, the NiOx layer is used to replace PEDOT:PSS as the hole transport layer. Since longer UV Ozone treatment time reduces transmission of NiOx, the device with two minutes UV Ozone treatment of NiOx exhibit the optimal PCE of 5.37%. Although PCE of the NiOx device is not as good as that of the PEDOT:PSS device, the stability of the devices with NiOx is much better.
Lan, Shang-Che, and 藍上哲. "The Structure-Property Relationships of P-typed Conjugated Polymers and Small Molecules in Bulk-Heterojunction Organic Solar Cells." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/43898927828436100857.
Повний текст джерела國立交通大學
材料科學與工程學系所
103
Solution-processed organic solar cells (OSCs) prepared through roll-to-roll or inject printing and used within inexpensive, lightweight, flexible devices are being considered as next-generation energy sources. Bulk heterojunctions (BHJ), in which a conjugated polymer (molecule) as a p-type material is blended with a fullerene derivative (e.g., PC61BM) as an n-type material, are the most successful active layer structures for OSCs. In this system, the morphology of BHJ layer play an important role for the high efficient OSCs due to it controls the efficiency of photon-to-current. At early stage, the design and synthesis of novel conjugated polymers and molecules mainly focused on tuning electronic properties, including bang-gaps and energy levels. However, other physical properties, such as solubility, miscibility, and crystallinity, are also important for OSCs, because they could affect the morphology of BHJ layer and the processed condition; therefore, the structure-property relationships of those conjugated materials are worth to be studied. In this thesis, we aimed the investigation at the effects of conjugated-backbone frameworks and alky-chain architectures on molecular stacking characteristics and corresponding processing conditions of devices. In the first part, we insert an extra 4-alkyl thiophene unit as conjugated spacer between benzotrithiophene (BTT) and benzothiadiazole(BT) to synthesize new donor-acceptor conjugated polymer, PBTT4BT. We found this polymer exhibited semi-crystalline characteristic, while the original polymer, PBTTBT, is amorphous. When we used this polymer in bulk heterojunction photovoltaic device applications, the device of PBTT4BT/PC61BM showed an efficiency of 5.6 % which is higher than the device of PBTTBT/PC61BM. On the other hand, we also use benzooxadiazole (BO) to synthesize another polymer, PTT4BO, which has a configuration of PBTT4BT but lower HOMO level. Because PBTT4BO exhibited unsatisfactory solubility limiting the molecular weight, we changed the alkyl-chain bulk on BTT unit to get two high molecular weight polymers, PBTT4BO-C13C11 and PBTT4BO-C13C8. The bulk of the alkyl side chains of these polymers impacted their solubility and molecular interactions, as well as their absorptions properties, crystallinities, and BHJ morphologies. The best efficiency was obtained from the device containing annealed PBTT4BO-C13C8 and PC71BM (w:w/1:2) active layer that had been maintained at 150 °C for 15 min with a power conversion efficiency of 6.2%. Then for the second part, we studied structure-property relationship of small molecules with a configuration of acceptor-donor-acceptor. At first, we synthesized three new small molecules- TB3t-BT, TB3t-BTT, and TB3t-BDT- that feature different central cores, including bithiophene, benzotrithiophene, and benzodithiophene units, respectively. The molecular structures of these cores significantly affected the melting and crystallization behaviors as well as formation of crystalline domains in blend films with PC61BM, which leads different efficiencies and processing conditions. Then we further synthesized three new molecules based on the structure of TB3T-BT by attaching different lengths of alkyl chains on central bithiophene unit. Those four molecules displayed two diffraction peaks of the (100) plane in their GIWAXS patterns, indicating polymorphism. Interestingly, the relative intensity of these two peaks changed when we modified the length of the central side chain, suggesting that it also affected the preferred stacking of the small molecules. In addition, the crystallinity within BHJ layer was also affected by side-chain arrangement, the molecules with identical molecules show comparatively better crystalline characteristic resulting higher performance.
Duryodhan, Sahu, and 薩戶. "Synthesis and Applications of Novel Narrow Band-gap Conjugated Polymers, Dyes and Their Supramolecular Interactions for Organic Solar Cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/61332056407619837135.
Повний текст джерела國立交通大學
材料科學與工程學系
99
The prime aim of this review is to bring together the areas of narrow band-gap conjugated polymers, dyes, and the supramolecular self assemblies of both dyes and polymers for the applications of organic solar cells. In the first chapter, a brief introduction of evolution of different types of solar cells has been given and also surveyed the literatures for the different structures of conjugated systems which can be efficient for the applications of organic solar cells. In the Second chapter two series of novel symmetrical acceptor-donor-acceptor organic sensitizers (M1-M3 and M4-M6) containing 3,6- and 2,7-functionalized carbazole (donor) cores, respectively, connected with two anchoring cyanoacrylic acid (acceptor) termini via different numbers (2 or 3) of conjugated thienyl linkers (w or w/o hexyl side-chains), were designed and synthesized. The effects of the molecular planarity originated from the central electron-donating 3,6- and 2,7-functionalized carbazole cores on device performance were studied. A structure-based density functional theory (DFT) calculation confirmed the efficiencies of the dyes being related to the coplanarity of the carbazole cores with respect to the linked thiophene units. Molecular orbital analyses reflected the characterstics of the carbazole-based highest occupied molecular orbitals (HOMOs) and acid-based lowest unoccupied molecular orbitals (LUMOs) along with the bridged thiophene units were essential for strong conjugations across the donor-acceptor groups, while time-dependent density functional theory (TDDFT) calculations allowed the assignment of HOMO–LUMO transitions (>90%) of the low energy bands in these new systems. Among these dyes, the best dye sensitized solar cell (DSSC) performance was obtained from the DSSC device containing M1, bearing 3,6-functionalized carbazole center linked by two symmetrical bithiophene groups, with an overall power conversion efficiency (讯) value of 4.82%, an open circuit voltage (Voc) of 0.61 V, a short circuit photocurrent density (Jsc) of 12.66 mA/cm2, and a fill factor (FF) of 0.62 under standard AM 1.5 sunlight with a maximum incident photon to current conversion efficiency (IPCE) of 68%. Furthermore, it is very impressive to observe the IPCE and Jsc values of the DSSCs in TiO2-based thin films (3 μm) containing M1 and M5 dyes were higher than those of the DSSC containing ruthenium-based N719 sensitizer. In the third chapter four novel symmetrical organic dyes (S1-S4) configured with acceptor-donor-acceptor (A-D-A) structures containing electron donating fluorene (S1 and S2) and N-alkyl dithieno[3,2-b:2',3'-d]pyrrole (DTP) (S3 and S4) cores terminated with two anchoring cyanoacrylic acids (as electron-acceptors) were synthesized and applied to dye-sensitized solar cells (DSSCs). The DSSC device based on S2 dye showed the best photovoltaic performance among S1-S4 dyes: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 76%, a short circuit current (Jsc) of 12.27 mA/cm2, an open circuit voltage (Voc) of 0.61 V, a fill factor (FF) of 0.63, and an overall power conversion efficiency (η) of 4.73%. Besides, the utilization of chenodoxycholic acid (CDCA) as a co-adsorbent in the DSSC device based on S3 dye showed a significant improvement in its η value (from 3.70% to 4.31%), which is attributed to the suppression of dye aggregation on TiO2 surface and thus to increase the Jsc value eventually. In the fourth chapter a series of novel low-bandgap triphenylamine-based conjugated polymers (PCAZCN, PPTZCN, and PDTPCN) consisting of different electron-rich donor main chains (N-alkyl-2,7-carbazole, phenothiazine, and cyclopentadithinopyrol, respectively) as well as cyano- and dicyano-vinyl electron-acceptor pendants were synthesized and developed for polymer solar cell (PSC) applications. The polymers covered broad absorption spectra of 400-800 nm with narrow optical bandgaps ranging 1.66-1.72 eV. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of the polymers measured by cyclic voltommetry (CV) were found in the range of -5.12 to -5.32V and -3.45 to -3.55 eV, respectively. Under 100 mW/cm2 of AM 1.5 white-light illumination, bulk heterojunction (BHJ) photovoltaic devices comprising of an active layer of electron donor polymers (PCAZCN, PPTZCN, and PDTPCN) blended with electron-acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) in different weight ratios were investigated. The photovoltaic device containing donor PCAZCN and acceptor PC71BM in 1:2 weight ratio showed the highest power conversion efficiency (PCE) of 1.28 %, with Voc = 0.81 V, Jsc = 4.93 mA/cm2, and FF = 32.1%. In the fifth chapter a series of novel hydrogen-bonded (H-bonded) cross-linking polymers were generated by complexing various proton-donor (H-donor) solar cell dyes containing 3,6- and 2,7-functionalized electron-donating carbazole cores bearing symmetrical thiophene linkers and cyanoacrylic acid termini with a proton-acceptor (H-acceptor) side-chain homopolymer carrying pyridyl pendants (with 1/2 molar ratio of H-donor/H-acceptor). The supramolecular H-bonded structures between H-donor dyes and the H-acceptor side-chain polymer were confirmed by FTIR measurements. The effects of the supramolecular architecture on optical, electrochemical, and organic photovoltaic (OPV) properties were investigated. From DFT (density functional theory) calculations, the optimized geometries of organic dyes reflected that the carbazole cores of H-donor dyes were coplanar with the conjugated thiophenes and cyanoacrylic acids, which is essential for strong conjugations across the donor-acceptor units in D1-D4 dyes. Under 100 mW/cm2 of AM 1.5 white-light illumination, bulkheterojunction (BHJ) OPV cell devices containing an active layer of H-bonded polymers (PDFTP/D1-D4) as an electron donor blended with [6,6]-phenyl C61 butyric acid methyl ester (PCBM) as an electron acceptor in a weight ratio of 1:1 were explored. From the preliminary investigations, the OPV device containing 1:1 weight ratio of H-bonded polymer PDFTP/D2 and PCBM showed the best power conversion efficiency (PCE) value of 0.31% with a short-circuit current (Jsc) of 1.9 mA/cm2, an open-circuit voltage (Voc) of 0.55 V, and a fill factor (FF) of 29%, which has a higher PCE value than the corresponding H-donor D2 dye (PCE = 0.15%) or H-acceptor PDFTP homopolymer (PCE = 0.02%) blended with PCBM in 1:1 weight ratio.
Hsu, Jhih-Yang, and 許志揚. "Synthesis and Characterization of Naphtho[1,2-d:5,6-d']bis([1,2,3]triazole)-based Wide-Bandgap Conjugated Polymers for Organic Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/4ahn76.
Повний текст джерела國立交通大學
應用化學系碩博士班
106
In this study, we successfully synthesized two D-A wide-bandgap conjugated polymers, PNTzBDT1 and PNTzBDT2, based on the naphtho[1,2-d:5,6-d']bis([1,2,3]triazole (NTz) and benzo[1,2-b:4,5-b']dithiophene (BDT) as the monomers, both of these two polymers have the optical bandgap are 1.9 eV, and are applied in the non-fullerene polymer solar cells. By introducing the triazole unit, we can place the side chain on the nitrogen atom rather than the thiophene in the main chain, hence the co-planarity of the π-conjugated system will be increased. We use the alkyl side-chain with various bulkiness on the BDT and NTz monomers respectively, however, the total carbon number is the same for the two polymers, to see how the different side-chain on the polymers affect the solubility, physical, chemical properties and the molecular packing in the thin-film solid state. According to the computational calculations, PNTzBDT1 has the better co-planarity, therefore, it has the better inter-chain packing, stronger π-π interaction and poorer solubility, whereas PNTzBDT2 shows the curved backbone, results in weaker inter-chain interaction and better solubility. The UV-Vis absorption of the two polymers and PC71BM are partially overlapping, consequently, we choose the non-fullerene acceptor, ITIC, as the n-type material to make up the absorption in long wavelength region. Bulk heterojunction solar devices were fabricated with inverted architecture (ITO/ZnO/Active layer/Ag/MoO3). The device using the PNTzBDT2:ITIC shows a PCE of 5.26% with a Voc of 0.88 V, a FF of 46.8%, and a Jsc of 12.75 mA/cm2. Under similar conditions, the device using the PNTzBDT1:ITIC presents a PCE of 7.37% with a high Voc of 0.94 V, a FF of 55.8, and a Jsc of 14.04 mA/cm2.
Tseng, Cheng-Chun, and 曾鉦鈞. "Synthesis and Characterization of Highly Crystalline Conjugated Polymers Based on 5,6-Difluorobenzo[2,1,3]thiadiazole with Selenophene Units for Applications in Organic Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/8hzpnq.
Повний текст джерела國立交通大學
應用化學系碩博士班
105
Selenophene has several advantages such as high polarizability and high quinoidal population which endow many selenophene-based materials with narrower optical bandgap, enhance light-harvesting ability and higher crystallinity. These beneficial properties lead to the improved charge carrier mobiliies in transistor devices or higher photocurrents in OPV devices. The traditional method to synthesize 3-alkyl selenophene is quite complicated and costly. We successfully design an efficient way to simplify the synthesis of selenophene. We utilize selenophene to synthesize three donor-acceptor copolymers consisting of 5,6-difluorobenzo[2,1,3]thiadiazole (FBT) and selenophene called PFBT2Th2Se, PFBT2Se2Th and PFBT4Se, respectively. Selenophene has higher intramolecular charge transfer ability with FBT than thiophene. Therefore, the polymers containing selenophene display more red-shifted absorption. The selenophene-containing polymers also show temperature-dependent absorption spectrum, indicating that the incorporation of selenophene does not affect the crystalline behavior of the polymers. Furthermore, the results from differential scanning calorimeter (DSC) confirm that these three polymers have crystalline behavior since it shows the obvious melting point upon heating and the clear crystallization point upon cooling. The combination of these characteristics enhances the charge transport efficiency. Hence, the devices which utilize these selenophene-containing polymers can obtain impressive current density (>20 mA/cm2). To gain a deeper insight into the nanoscale morphology and orientation of the photoactive layers, the grazing-incidence wide-angle X-ray diffraction (GIWAXD) was employed. The results suggest that the three polymers blended with PC71BM adopt face-on orientation which is beneficial for charge carrier transport in the vertical direction in the active layer. Organic photovoltaic devices are fabricared with inverted atchitecture (ITO/ZnO/Active layer/MoO3/Ag). The device using PFBT2Th2Se:PC71BM shows a PCE of 8.68 % with a Voc of 0.68 V, an FF of 69.1 %, and a high Jsc of 18.46 mA/cm2. Under similar conditions, the device using the PFBT2Se2Th:PC71BM blend presents a PCE of 9.02% with a Voc of 0.66 V, an FF of 65.0 %, and an impressive Jsc of 21.02 mA/cm2. Furthermore, the device with PFBT4Se displays a PCE of 8.92 % with a Voc of 0.62 V, FF of 63.6 %, and a superior Jsc of 22.63 mA/cm2 which represents one of the highest current densities from PSCs reported in the literature.
Wu, Jhao-Lin, та 吳昭霖. "Study of low band-gap π-conjugated polymers for organic photovoltaics and perylene diimide derivatives as electron transporting materials for perovskite solar cells". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/283g3b.
Повний текст джерела國立臺灣大學
化學研究所
106
This thesis can be divided into 2 parts. The first was concentrated on designing and synthesizing donor materials for the organic photovoltaics (OPVs). The second part was focused on developing of electron transporting materials for the perovskite solar cells (PVSCs). In the first part, we have synthesized and characterized a series of diketopyrrolopyrrole (DPP)-oligothiophene copolymers, of which the number of regioregular oligothiophene ring (2T, 3T and 4T) and the arrangement of the alkyl side-chain on regioirregular quarterthiophene (4T0, 4T1 and 4T2) are variable. The side chains with regioregular lead to more planar copolymer backbones and higher short circuit current (JSC), but backbone torsion (due to regioirregular side chains) generates greater open-circuit voltages (VOC) for DPP-oligothiophene copolymers. The increasing thiophene ring progressively raises HOMO energy level of copolymers but marginally affects their band gaps. Additionally, the HOMO energy level was found declined significantly with side-chain regioirregularity, because of reducing length of π-conjugation. The HDDPP4T0 exhibits the strongest absorption, extensive network structure, and high hole mobility (µh = 6.04 × 10-4 cm2 V-1 s-1). These characteristics contribute to the exceptional high JSC of 18.96 mA cm-2 for OPV with PCE = 6.12%. However, the HDDPP4T1 having an optimal combination of π-conjugation and energy level affords the second highest VOC (0.73 V) and the third highest JSC (16.89 mA cm-2), resulting the best PCE of 7.51 % among all. X-ray scattering, transmission electron microscopy, atomic force microscopy, and space-charge-limited-current (SCLC) easurements reveal that the solvent additive of diphenylether (DPE) enables PC71BM-blended copolymers thin film in crystallinic fibril with enhanced hole mobility. In the second part, we have developed and demonstrated three solution processable perylene diimides, i.e., X-PDI, X = H, F, or Br, as nonfullerene electron accepting and electron transporting materials in inverted PVSCs. Whereas H-PDI or F-PDI performs unsatisfactorily, our best PVSC is based on Br-PDI exhibiting PCE of 3.23%, which is just a bit shy of 4.13% of fullerene (PC61BM) PVSCs. Through a series of physical, spectroscopic, and microscopic studies, we have understood that the low solubility of F-PDI is a major factor causing the poor quality of the thin film, rendering virtually no photovoltaic effect for F-PDI. Although the solubility of H-PDI is better than F-PDI, the inferior electron mobility and conductivity make H-PDI PVSCs have relatively worse performance. Having the highest solubility, electron mobility, and conductivity among X-PDI, Br-PDI based PVSCs are almost as efficient as PC61BM based PVSCs. Within the ZnO NP as a CBL in the PVSCs, the PCEs of PVSCs based on X-PDI or PC61BM are significantly improved to 7.78%, 10.50%, and 11.07%, respectively.We infer that the CBL of ZnO NP has the function of interspacelling on the defect of X-PDI or PC61BM thin film, reducing the direct contact of Ag cathode to the perovskite material. Due to the strong molecular interaction, F-PDI aggregates significantly in thin film, creating too many and too large defects to be remedied or improved with or without CBL of ZnO NP. Very poor electron mobility and conductivity of F-PDI are two other factors devastating its PVSCs. Through this study, we have demonstrated that the simple mono-bromine substituted perylene diimide (Br-PDI), is solution processable and has potential for use as a non-fullerene electron accepting and electron transporting material in inverted PVSCs.
Siram, Raja Bhaskar Kanth. "Investigation Of Phase Separation In Bulk Heterojunction Solar Cells Via Self-assembly Approach And Role Of Organic Fluorine In Design Of n-type Molecular Semiconductors." Thesis, 2012. http://hdl.handle.net/2005/2306.
Повний текст джерелаGavvalapalli, Nagarjuna. "Breaking the barriers of all-polymer solar cells: Solving electron transporter and morphology problems." 2012. https://scholarworks.umass.edu/dissertations/AAI3545923.
Повний текст джерела