Дисертації з теми "OPTOELECTRONIC DEVICE APPLICATIONS"
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Guptah, Vinod Kumar. "Growth on patterned substrates for optoelectronic device applications." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267027.
Повний текст джерелаAlexandropoulos, Dimitrios. "Theoretical studies of GaInNAs for optoelectronic device applications." Thesis, University of Essex, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274313.
Повний текст джерелаPratt, Andrew Richard. "Control of indium migration on patterned substrates for optoelectronic device applications." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307775.
Повний текст джерелаGrudowski, Paul A. "The metalorganic chemical vapor deposition of III-V nitrides for optoelectronic device applications /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Повний текст джерелаXin, Huoping. "Gas-source molecular beam epitaxy of GaInNAs and Ga(In)NP for electronic and optoelectronic device applications /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9970681.
Повний текст джерелаKim, Danny. "Dry passivation studies of GaAs(110) surfaces by Gallium Oxide thin films deposited by electron cyclotron resonance plasma reactive molecular beam epitaxy for optoelectronic device applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63140.pdf.
Повний текст джерелаCheung, Chor-keung. "The construction of a focused low energy positron beam facility and its application in the study of various optoelectronic materials." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36995770.
Повний текст джерелаCheung, Chor-keung, and 張初強. "The construction of a focused low energy positron beam facility and its application in the study of various optoelectronic materials." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37434925.
Повний текст джерелаLi, Cheng. "Metal oxide films for optoelectronic device application." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648598.
Повний текст джерелаDavis, Nathaniel J. L. K. "Applications of spectral management in optoelectronic devices." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/263670.
Повний текст джерелаLee, Kyoung-Keun. "Implementation of AlGaN/GaN based high electron mobility transistor on ferroelectric materials for multifunctional optoelectronic-acoustic-electronic applications." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28209.
Повний текст джерелаCommittee Chair: William. Alan Doolittle; Committee Member: Jeffrey Nause; Committee Member: Linda S. Milor; Committee Member: Shyh-Chiang Shen; Committee Member: Stephen E. Ralph.
Jones, Gareth Francis. "Modification of graphene for applications in optoelectronic devices." Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/31537.
Повний текст джерелаLee, Min-Hsuan. "Solution-processable organic-inorganic hybrid transparent electrode for optoelectronic applications." HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/320.
Повний текст джерелаDrew, Stephen. "Symmetric Gain Optoelectronic Mixers for LADAR Applications." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/DrewS2009.pdf.
Повний текст джерелаLee, Jeffrey Chi Wai. "Chiral photonic crystals and their potential applications /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202009%20LEE.
Повний текст джерелаCheung, Yuk Lung. "Application of silicon display for photo printer /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20CHEUNG.
Повний текст джерелаIncludes bibliographical references (leaves 80-82). Also available in electronic version. Access restricted to campus users.
Lee, Siew-wan Alex. "Optical properties of intermixed quantum wells and its application in photodetectors /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21326411.
Повний текст джерелаIshibashi, Jacob Shotaro Afaga. "BN Isosteres of Acenes for Potential Applications in Optoelectronic Devices." Thesis, Boston College, 2017. http://hdl.handle.net/2345/bc-ir:107613.
Повний текст джерелаThis dissertation describes progress in the field of polycyclic boron- nitrogen-containing systems, especially for potential application in organic-based optoelectronic devices and hydrogen storage materials. The replacement of a BN unit for a CC unit organic compounds (BN/CC isosterism) can have a profound effect on the electronic structure and even function of a given molecular topology without changing its physical structure very much. Direct comparison between a BN-containing molecule and its direct all-carbon analogue is crucial to establishing the origin of these differences. The synthesis and optoelectronic characterization of boron- nitrogen-containing analogues of naphthalene, anthracene, and tetracene are disclosed. Also examined herein is the aromatic Claisen rearrangement applied to an azaboryl allyl ether. Finally, the chemistry of saturated BN heterocycles, including an iridium-catalyzed transfer dehydrogenation method for synthesizing BN-fused azaborines. Also disclosed is the actual application of these cyclic amine-boranes in supplying hydrogen for a proton exchange membrane (PEM) fuel cell
Thesis (PhD) — Boston College, 2017
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
Tse, Chui-wan. "Rhenium containing hyperbranched polymers for photonic applications." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38574512.
Повний текст джерелаMontero, Martín Jose María. "Charge transport in organic semiconductors with application to optoelectronic devices." Doctoral thesis, Universitat Jaume I, 2010. http://hdl.handle.net/10803/10474.
Повний текст джерелаla movilidad dependiente del campo y de la densidad ha sido dado por medio de una ley universal de escalado. Los espectros de capacidad y los tiempos de tránsito han sido examinados con la inclusión de la movilidad dependiente del campo eléctrico y comparado con los datos experimentales, verificándose el modelo teórico planteado. Se ha descrito la movilidad de portadores de carga a través de un modelo de transporte con una densidad exponencial de trampas. Se han utilizado técnicas de espectroscopía de impedancia para explicar la movilidad dependiente del campo eléctrico en términos del múltiple atrapamiento ejercido por los estados energéticamente localizados. Este modelo ha explicado de forma coherente los espectros de capacidad recogidos en medidas experimentales, particularmente su comportamiento a bajas e intermedias frecuencias. La respuesta de los OLED (polímero SY) ha sido estudiada en los regímenes estacionario y transitorio. En el régimen estacionario, se han descrito las corrientes de fuga a bajos potenciales. Se ha
analizado la existencia de mayor corriente circulando por el perímetro que por el área del dispositivo. En el régimen transitorio, se ha
proporcionado una explicación sobre las colas de luz emitida observadas al cesar la perturbación de potencial escalón: procede de la inyección
limitada de electrones en el cátodo.
Chun, Carl S. P. (Shun Ping). "Investigation of GaAs MESFET amplifier topologies for optoelectronic receiver applications." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/14813.
Повний текст джерелаSustersic, Nathan Anthony. "The growth and characterization of silicon-germanium devices for optoelectronic applications." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 3.10 Mb., 83 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:1435828.
Повний текст джерелаGan, Haiyong. "Electro-optic Polymer Based Fabry-Perot Interferometer Devices for Optoelectronic Applications." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195839.
Повний текст джерелаTse, Chui-wan, and 謝翠雲. "Rhenium containing hyperbranched polymers for photonic applications." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38574512.
Повний текст джерелаZaidi, Tahir. "Ferromagnetic and multiferroic thin films aimed towards optoelectronic and spintronic applications." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/41110.
Повний текст джерелаROONEY, MILES. "Self-assembled, nanostructured organic materials for applications in electronics and optoelectronic devices." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2018. http://hdl.handle.net/10281/199099.
Повний текст джерелаthe investigation of two methods for molecular control of the nano-morphology of opto-electronic devices. Firstly, a photocrosslinking method for creating insoluble semiconductor layers suitable for organic photovoltaic devices. A large series of squaraine based semiconductors are investigated in a bulk heterojunction device. This approach is extended to diketopyrrolopyrrole and naphthalene diimide semiconducting cores. Detailed study of the materials film structure is carried out. The second approach is an investigation of the applicability of latent pigments for organic opto-electronics. A series of organic photovoltaics are produced in planar bilayer and bulk heterojunction architectures. The thin film devices are tested with a variety of interlayers and processing parameters. The control of the nanostructure of these thin film devices is examined with X-ray studies. Incorporating X-ray reflectivity, Specular x-ray, Gradient temperature X-ray and grazing wide angle x-ray studies. In this manner the bulk and interfaces of thin film devices can be examined and characterised. The latent pigment approach is also applied to the field of organic field effect transistors as the active semiconducting layer. The solvent resistant nature of a parent semiconducting pigment shows a substantial benefit to the fabrication of such devices. The unique crystalline rearrangement which occurs upon deprotection of a latent pigment results in an improvement in charge carrier mobility of up to three orders of magnitude while extending the processing possibilities of the subsequent deposition steps required to complete an organic field effect transistor These two techniques are developed with the thoughts of industrial compatibility in mind. As such, a novel synthetic method for facile, cheap, and environmentally friendly production of organic semiconductors is explored. A micellar reaction environment is created through the use of the common surfactant and drug excipient Kolliphor EL. The unique oxygen free core of this surfactant offers a new environment for carrying out common cross coupling reactions such as Suzuki-Miyaura, Stille and Heck reactions in air and water at ambient temperature. High Yields of over 90% are recovered for complex organic semiconducting cores. The versatility of this approach is extended by the use of toluene as a co-solvent. This co-solvent system results in the development of an emulsion which can be used to perform complex chemistries. Emulsion chemistry offers a unique way to synthesis complex organic semiconductors with low metallic catalyst loading at high yield.
Rezaei, Mazinani Shahab. "Development of novel organic optoelectronic technologies for biomedical applications." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEM028/document.
Повний текст джерелаOrganic optoelectronic devices have many promising qualities for biomedical applications. Organic photodetectors (OPD), one type of such devices, have yet to be utilized for the detection of signals in the brain, to the best of our knowledge. The goal of this thesis was to explore the use of OPDs, based on different electron-donor and -acceptor materials in neuroscience applications. Different types of minimal-structure OPDs are presented, which have an excellent sensitivity and a high potential for incorporation into existing microfabrication methods. The organic sensors were utilized for monitoring the brain’s intrinsic optical signals and fluorescent calcium dynamics. Additionally, another aspect of these devices is presented (in combination with organic electrochemical transistors (OECT)): neuroinspired electronics, electronics that mimic biology. This thesis establishes the promise of OPDs for monitoring brain activities, which would lead to their integration, as high-sensitive micron-scale optical sensors in organic neural probes. Such device would result in exploring optical biological activities in the deep brain on the cellular level and would push the frontiers of optical-electrophysiology by giving a better understanding of complex mechanisms of the brain function and neurodegenerative diseases
劉彥泓. "Nano Texturization by Plasma for Optoelectronic Device Applications." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/17582493898868985462.
Повний текст джерелаHsu, Tsung-Han, and 許宗翰. "Study of Metal Silicide amd Nanomaterials for Optoelectronic Device Applications." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/97783933953231557789.
Повний текст джерела國立臺灣大學
材料科學與工程學研究所
94
Metal silicide and photonic crystals play important roles in optoelectronic devices. In this thesis, we study optical properties of these two kinds of materials. The first part of thesis is metal silicide, titanium silicide with. Titanium silicide is very suitable as gate materials in next-generation photo detector for its good thermal stability and lowest sheet resistance among all of metal silicides. We characterize the optical properties , reflective index and extinction coefficient, of titanium silicide by ellipsometryin the visible regime for photodetector application. Since ArF laser (193nm) and F2 laser (157nm) are light sources of optical lithography for the generation of less than 100 nm , we also characterize optical constants of titanium silicide in the 193nm and 157nm wavelength regimes. We find titanium silicide has high reflectance in the wavelength regime 450nm~750nm, which is an important range for photodetector. Therefore, we designe and fabricate an antireflective coatings for wavelength between 450nm~750nm, then the reflectance in the range is reduced to less than 5%. For optical lithography application, we also fabricate bottom antireflective coatings of titanium silicide in 193nm and 157nm for the reduction of standing-wave effect.. In the photonic crystals study, we use well-mixed colloidal nanomaterial in different sizes to form binary opals. By this method, we can fine-tune the photonic bandgap within 1~2nm. Besides, by changing the size and contents of the small colloids, we can be aware of how the smaller one affects the bandgap and crystal structure of binary opals. We also find the smallest size of doped collide has significant effect.
YING, CHOU CHENG, and 周承穎. "Development of flexible conductive thin films for optoelectronic device applications." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/85557505423796081260.
Повний текст джерела國立臺灣師範大學
機電科技學系
101
The aim of this study is to use a simple process with a lift-off and electrophoresis plating technique to fabricate the conductive thin film on flexible substrate with CNTs (Carbon nanotubes). The CNTs are studied as the electrode material and have the potential owing to its high conductivity and the convenience of the fabricating process. To deploy the CNTs, we apply SDS (Sodium dodecyl sulfate) as the dispersant. Here, the substrate is employed PDMS (Polydimethylsiloxane), which is a group of polymeric organosilicon compounds. For the direct photolithography on PDMS, the surface of PDMS should be not only hydrophilic, but more flat so that the photoresist could be spun on the surface evenly. After the process of photolithography, the patterns of electrode can be defined on the surface. Based on this direct process, the complicated electrode patterns can be easily defined and its pattern would not be deformed. In electrophoretic plating technique, by applying different voltages and time for abtained optimized parameters, it can be deposited CNTs on PDMS well. After depositing, the CNTs can be transferred to PDMS. Finally, we use SEM, FTIR, and Raman Spectrum for measuring the surface and properties of CNT. Therefore, this study provides a novel and simple way to fabricate the conductive thin films and through the complicated electrode pattern defined, the application of thin films for photoelectric sensors could be easily used in this work.
Hsieh, Hsien-Chieh, and 謝顯傑. "Development of functional light-extraction microstructure for optoelectronic device applications." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/44016878160469140278.
Повний текст джерела國立臺灣師範大學
機電科技學系
101
With the increasing downscaling of electro-optical components and the development of microelectromechanical systems (MEMS), microlens array is attracting more attention for various applications, including optical communications, image processing, lab-on-a-chip techniques, high-definition projection displays and other photonic devices. Hence, many manufacture processes for microlens have been described, such as the thermal reflow, laser micromachining, gay-scale mask, ink-jet printing and proton beam writing. The variety of microlens array can usually be employed for lighting design for improving their outcoupling efficiency or enhancing the light extraction efficiency. Compared with the conventional photolithography, a diffuser approach can be used in developing a process to fabricate the microlens array. The advantages of a diffuser include a simple process and shape control of microlens array. This study presents a simple and effective diffuser approach to fabricate a plastic microlens array with controllable shape and full fill-factor, and combined the methods of the soft lithography and plastic replication. It can be found that the microlens array of PDMS structures is an extremely high full fill-factor. The fill-factor in this study is approximately 100%. In conclusion, the full fill-factor PDMS microlens array can be successfully fabricated by a diffuser approach. The precise shape of microlens is needed by using the well-controlled process parameters. The curves of the microlens are fitted by using sag equation. Thereupon, this study can be helpful to a new route to range of functional optical applications.
Wu, Hung-Chin, and 吳泓錦. "Side Chain Engineering on Polymeric Semiconductors for Optoelectronic Device Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/32858534823016129730.
Повний текст джерела國立臺灣大學
化學工程學研究所
103
Polymeric semiconductors have received great attentions for organic electronic and optoelectronic devices, such as field-effect transistors (FETs), photovoltaic cells (PVs), and memory devices. In the recent progress of polymer community, side chains are act as a crucial component in the design of novel conjugated polymers. They not only directly relate to the solubility but also affect the molecular packing motifs and thin film morphologies. The goal of this thesis is to address the effect of conjugated or alkyl side chain structures on the polymer thin film morphologies and the optoelectronic properties. In addition, the field-effect mobilities, photovoltaic, or memory characteristics are also probed to investigate the side chain engineering design on polymeric semiconductors for optoelectronic devices systematically. Three different strategies are explored in this thesis, as shown in followings: 1. Syntheses of two-dimensional branched thiophene extended octithiophene‐based conjugated polymers for field-effect transistors and photovoltaic cells: In Chapter 2, three octithiophene (8T)-based conjugated copolymers, including P8TSe, P8TT, and P8TTT, have been synthesized. The larger atomic radius selenium (Se) atom possesses higher polarizability than sulfur (T), inducing stronger intermolecular interactions in solid state. Also, 8T moiety could significantly lower the HOMO level and lead to the enhanced open circuit voltage because of its branched conformation. The hole mobilities of these 8T-based copolymers were in the range of 1.32×10-5 to 5.00×10-5 cm2V-1s-1 with on/off ratio of 104. Among them, P8TTT showed better characteristics than the other polymers due to the fused-ring TT can promote self-organization and minimize the steric interactions. The power conversion efficiencies (PCE) of the copolymers/PC71BM based photovoltaic cells were in the range of 1.28 - 2.30% under the illumination of AM 1.5G (100 mW cm-2). In particular, P8TTT showed the best PCE of 2.81%, as the blend films are prepared from the mixed solvent of o-dichlorobenzene (DCB) and 1,8-diiodoctane (DIO) (DCB/DIO = 97%:3% by volume). In Chapter 3, the synthesis, morphology and optoelectronic device applications of 2D extended quaterthiophene (4T)- and octithiophene (8T)-vinylene conjugated polymers, P4TV and P8TV, were explored. P4TV and P8TV exhibited smaller energy band gaps of 1.69 and 1.78 eV than that of parent polythiophenes, respectively, due to the reduced conformation distortion by the vinylene linkage. The highest field-effect hole mobilities of P4TV and P8TV were 0.12 and 0.0018 cm2V-1s-1, respectively, with on/off ratios around 104-105. In addition, the power conversion efficiency (PCE) of the P4TV/PC71BM based photovoltaic cells under the illumination of AM 1.5G (100 mW cm-2) was 4.04 %, which was significantly higher than that of P8TV/PC71BM with 2.69 %, due to its superior charge transport ability. However, P8TV had a better environmental stability attributed to its low-lying HOMO energy level. 2. Syntheses of main chain donor tethered side chain phenanthro[9,10-d]imidazole acceptor conjugated polymers for high performance flexible resistive memory devices: In Chapter 4, a bipolar-recorded resistive memory device consisting of a single-layer donor-acceptor conjugated polymer fabricated on plastic polyethylene naphthalate (PEN) have been developed. The newly designed conjugated polymer with a main-chain donor of fluorene and thiophene and a side-chain acceptor of phenanthro[9,10-d]-imidazole (PFT-PI) was synthesized as an active memory material. The reproducible, nonvolatile flash switching characteristics of each sandwiched PEN/Al/PFT-PI/Al memory device was demonstrated under bending. The flexible nonvolatile resistor memory devices with low threshold voltages (±2 V), low switching powers ( 100 μW cm−2), large ON/OFF memory windows (104), good retention (>104 s) and excellent endurance against electric and mechanical stimulus. The simple and facile device fabrication was obtained from a single PFT-PI memory material, without using charge injection layers or a complex multilayer structure. In Chapter 5, the synthesis and resistive memory device characteristics of new donor-acceptor conjugated poly(arylene vinylene), PVC-PI, PVT-PI, and PVTPA-PI, have been explored. The studied polymers possess similar HOMO energy levels (-5.08 ~ -5.18 eV), but with different LUMO energy levels (-2.24, -3.40, and -2.60 eV for PVC-PI, PVT-PI, and PVTPA-PI, respectively). The PVC-PI flexible memory with the sandwich configuration of PEN/Al/polymer/Al reveals the volatile static random access memory (SRAM) characteristic while the PVTPA-PI device exhibits the nonvolatile write-once-read-many-times (WORM) switching behavior. The above two devices could operate at low voltages (less than 2.5 V) with high ON/OFF current ratios (over 104) and exhibit excellent durability upon repeated bending tests. The PVT-PI device, however, only shows a diode-like electrical behavior. The polymer conformation affects the strength of D-A electrical polarization and charge trapping ability, leading to the variation on the volatility of the memory devices. 3. Effects of alkyl side chain design on charge transport: Synthesis, morphology, and stretchable transistor applications: In Chapter 6, three polymers with variant alkyl side chain structures (i.e. short linear, long linear, and branched alkyl side chains), namely P3HT, PTDPPTFT4, and PII2T, are evaluated for stretchable field-effect transistors. In addition, a facile method to efficiently identify suitable semiconducting polymers for organic stretchable transistors using soft contact lamination is described. In this method, the various polymers investigated are first transferred on elastomeric poly(dimethylsiloxane) (PDMS) slab, and subsequently stretched (up to 100 %) along with the PDMS. The polymer/PDMS matrix is then laminated on source/drain electrode-deposited Si substrates equipped with a PDMS dielectric layer. The polymer semiconductors can be repeatedly interrogated with laminate/delaminate cycles under different amounts of tensile strain, and the strain limitation of semiconductors enable different side chain structures can be derived. In Chapter 7, a series of isoindigo-based conjugated polymers (PII2F-CmSi, m=3-11) with alkyl siloxane-terminated side chains have been prepared, in which the branching point is systematically “moved away” from the conjugated backbone by one carbon atom. All soluble PII2F-CmSi (m=5-11) polymers exhibited hole charge carrier mobilities over 1 cm2V-1s-1, while the reference polymer with the same polymer backbone showed a much lower mobility of 0.13 cm2V-1s-1. PII2F-C9Si showed the highest mobility of 4.76 cm2V-1s-1, even though PII2F-C11Si exhibited the smallest π-π stacking distance at 3.379 Å. We concluded that it is beneficial that the branching site was further away from conjugated backbones to improve charge transport characteristics. The above studies demonstrate that the optoelectronic properties, charge carrier transport ability, solar cell efficiency, and memory behaviors can be manipulated using side chain engineering design. The device performances were tuned by controlling the chemical structures of conjugated side chains. Moreover, with variant alkyl side chain structures, the charge carrier mobility in stretched polymer thin films were changed, indicating the design of side chain on polymeric semiconductors plays a crucial role for next-generation electronic device application.
Chien, Shang-Chieh, and 簡上傑. "Functional Polymer Blends for Optoelectronic Applications: Morphology, Fabrication and Device Engineering." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/55959790724715985777.
Повний текст джерела國立交通大學
光電工程學系
100
Polymer optoelectronics fabricated through solution-processable methods commonly adopts polymer blends as the photoactive layer for improving their device performance. This dissertation proposed a series of functional polymer blends for various opto-electronical applications. The first part of this dissertation is to conceptually introduce a simple approach to realize nano-scaled interfacial modification for organic photovoltaic devices (OPVs). Through spontaneous vertical-phase-separation, a self-assembled poly(ethylene glycol) (PEG) buffer layer can be formed on the top-surface of the active layer, thereby naturally acting as a cathode buffer layer. The stable PEG materials can replace traditionally low-work-function metals, such as calcium (Ca), to improve the device stability. Furthermore, a series of systematical studies aiming for understanding the mechanism behind the formation of such self-assembled polymer buffer layer were performed from both thermodynamics and kinetics point of views. We found out that the surface energy of the substrate and the molecule weight of PEGs play essential roles in triggering the vertical-type morphological change. Moreover, not only for OPVs devices, this approach can also be employed to fabricate high-performance sky-blue, red and white polymer light-emitting diodes (PLEDs). The operating-voltage and the power efficiency have been improved after incorporating PEG. More importantly, we found that the charge-trapping effect lead to different enhancement mechanism between these PLEDs emitting different colors after the addition of PEG. Typical photoactive layer of polymer solar cells commonly consisted of one p-type conjugated polymer as the electron donor and one n-type electron acceptor. We additionally blended one functional fullerene derivatives, 1,2-dihydromethano-phenyl-C61-butyric acid methyl (Methano-PCBM), featuring a higher lowest unoccupied molecular orbital (LUMO) respect to that of PCBM, into the photoactive layer. Incorporating this Methano-PCBM, a larger energy offset between the highest occupied molecular orbital (HOMO) of the polymer donor and the LUMO of the acceptor can increase the open-circuit voltage (Voc); the resulting cascade energy level structure possibly also facilitated the charge transport in the devices. Further manipulation of this optimized photoactive layer could be employed to demonstrate efficient semi-transparent OPVs exhibiting high transparency. Finally, high-performance organic photodetectors featuring photomultiple effect have been demonstrated. The incorporation of near-infrared dyes not only resulted in electron-trapping behavior but their absorption was also optically complemented to the original film. As a result, high external quantum efficiencies (>7000%), high responsivities (32.4 A/W) and broadband response (300 nm to 1050 nm) have been achieved simtaneously at an extremely low operating voltage (–1.5 V).
Chih-YuanChen and 陳志源. "Study on MOCVD grown Gallium Oxide film for Optoelectronic Device Applications." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/40517571201474039421.
Повний текст джерела國立成功大學
光電科學與工程學系
100
This thesis focuses on growth of gallium oxide epitaxial film used metal organic chemical vapor deposition technology. Deposited on c-plane (0001) sapphire.I use a different growth conditions to discuss the impact on the quality of gallium oxide films. Changing the deposition temperature、chamber pressure, and oxygen flow to study the influence of the epitaxial film quality,try to choose a better growth parameters.After analysis, the optimized parameters: chamber pressure 15Torr、Oxygen flow 200 standard cubic centimeter per minute (sccm),Process temperature 500℃. Then a metal-semiconductor-metal solar-blind deep ultraviolet photodetector was fabricated on the β-Ga2O3 epilayer. The epilayer was grown on (0001) sapphire substrate using modified Emcore D180 MOCVD system.The metal organic source is TEGa, chemical reaction gas is oxygen. The as-grown β-Ga2O3 epilayer was annealed at 800 ºC in atmosphere or Oxygen or Nitrogen. Influence of surface states and point defects of β-Ga2O3 epilayers before and after N2 annealing are studied using room-temperature Photoluminescence (PL) and HR-XRD.We have shown that annealing single-crystalline β-Ga2O3 epilayer in Nitrogen atmosphere at 800 ºC can heal its surface states and point defects without disturbing crystal structure and quality.It also can improve the MSM photodetector performance of dark current and responsivity.
Murali, Krishna. "Engineering van der Waals Heterojunctions for Electronic and Optoelectronic Device Applications." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4778.
Повний текст джерелаVisvesvarayya PhD Scheme
Joyce, Hannah Jane. "Growth and characterisation of III-V semiconductor nanowires for optoelectronic device applications." Phd thesis, 2009. http://hdl.handle.net/1885/147722.
Повний текст джерелаWang, Chih-Feng, and 王誌鋒. "Thienopyrazine-based Donor-Acceptor Conjugated Polymers : Synthesis, Properties, and Optoelectronic Device Applications." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/29567520057371582908.
Повний текст джерела國立臺灣大學
化學工程學研究所
96
Donor-acceptor conjugated polymers have been widely investigated in recent years. By optimization of donor and acceptor structures, the conjugated copolymers can exhibit broad absorption from visible region to near-infrared range for electronic and optoelectronic applications, such as light-emitting diodes, photovoltaic cells, and thin film transistor. However, the electronic and optoelectronic properties of thienopyrazine-based conjugated polymers have not been fully explored yet. The goal of this thesis is to investigate the effects of donor-acceptor or donor-acceptor-donor structures on the electronic properties of thienopyrazine based conjugated polymers. In chapter 2, the optical, electrochemical, and field effect charge transport properties of the new thienopyrazine-based alternating donor-acceptor conjugated copolymers were explored. The new copolymers, Poly[5-(2,5-bis(decyloxy)phenyl)-2,3- bis(4-(2-ethylhexyloxy)phenyl)thieno[3,4-b]pyrazine] (PDPTP), Poly[5-(9,9-dioctyl- 9H-fluoren-2-yl)-2,3-bis(4-(2-ethylhexyloxy)phenyl)thieno[3,4-b]pyrazine] (PFPTP), Poly[5-(9-(2-ethylhexyl)-9H-carbazol-3-yl)-2,3-bis(4-(2-ethylhexyloxy)phenyl)thieno[3,4-b]pyrazine] (PCPTP) and Poly[2,3-bis(4-(2-ethylhexyloxy)phenyl)-5-(thiophen-2-yl) thieno[3,4-b]pyrazine] (PTPTP) had excellent solubility and broad optical absorption bands with absorption maxima at 540-950nm in thin film. The PTPTP exhibits the smallest band gap (0.98eV), indicating a stronger intramolecular charge transfer. The four polymers show the low ionization potentials (4.57-4.99 eV) and high electron affinity (3.26-3.49eV). The hole mobilities of PDPTP, PCPTP, and PTPTP are 2.62×10-6, 2.74×10-5, and 2.00×10-4 cm2V-1s-1. PTPTP has the highest hole mobility due to low band gap and strong intramolecular charge transfer.The AFM topographic images of the copolymers show smooth and amorphous phases. From these results, intramolecular charge transfer might be main impact on hole mobility. In chapter 3, thienopyrazine-based donor-acceptor-donor alternating conjugated copolymers were synthesized. The copolymers including Poly[5-(5-(2,5-bis(decyloxy)-4-methylphenyl)thiophen-2-yl)-2,3-bis(4-(2-ethylhexyloxy)phenyl)-7-(5-methylthiophen-2-yl)thieno[3,4-b]pyrazine] (PDDTTP), Poly[5-(5-(9,9- dioctyl-9H-fluoren-2-yl)thiophen-2-yl)-2,3-bis(4-(2-ethylhexyloxy)phenyl)-7-(thiophen-2-yl)thieno[3,4-b]pyrazine] (PFDTTP), and Poly[2,3-bis(4-(2-ethylhexyloxy)phenyl)-5 ,7-di(thiophen-2-yl)thieno[3,4-b]pyrazine] (PDTTP) exhibit broad optical absorption bands (662-816nm) and small optical band gaps (1.15-1.57eV). All polymers exhibit reversible oxidation and reduction and low ionization potential (4.62-4.98 eV). The hole mobility of PDDTTP, PFDTTP, and PDTTP are 7.24×10-4, 1.61×10-3 and 1.16×10-3cm2V-1s-1. The hole mobility of PFDTTP is the highest probably due to the relatively smooth and amorphous phase in thin film. According to these results, thienopyrazine-based donor-acceptor-donor copolymers combine small band gap and high carrier mobility. Such polymers may have potential optoelectronic device applications, such as thin film transistor and photovoltaic cells.
Wang, Chih-Feng. "Thienopyrazine-based Donor-Acceptor Conjugated Polymers : Synthesis, Properties, and Optoelectronic Device Applications." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1407200815023600.
Повний текст джерелаChang, Yuan-Ho, and 張源合. "Fabrication of Carbon-nitride Thin-Film by ECR-CVD for Optoelectronic Device Applications." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/68156078062746141474.
Повний текст джерела南台科技大學
電機工程系
94
Carbon-nitride is an interesting and important material owing to its several superior properties including high bulk modulus, high hardness, high decomposition temperature, high strength, high thermal conductivity and excellent resistance to corrosion and wear. However, crystalline carbon nitride (c-CN) is difficult to form, and hence its practical applications were greatly limited. The amorphous carbon-nitride (a-CN) thin-film deposited on silicon substrates is a highly functional wide-bandgap semiconductor material due to its similar material characteristics to c-CN. In addition, its optical bandgap is estimated to 4 eV above, making it a suitable candidate for development of short-wavelength or broad-band optoelectronic devices. In this thesis, a-CN thin-films were deposited on different substrates by an electron-cyclotron-resonant-chemical-vapor-deposition (ECR-CVD) technique. Properties of as-deposited films were adjusted by different microwave power and gas compositional ratios and were characterized by SEM, AFM, XRD, AES, UV/Visible Spectrophotometer and Raman Spectrophotometer. Experimental results showed that optical band-gaps of a-CN thin-films decreased with increasing microwave power or decreasing compositional ratio of nitrogen in the precursor. It is supposed that lower optical bandgaps were resulted from larger nitrogen-to-carbon ratios (N/C ratios) of films. Higher microwave power induced more intense plasma energy and more decomposition of nitrogen gas, thus making larger N/C ratios and lower optical bandgaps. On the contrary, if the proportion of nitrogen gas in the precursor increased, the plasma density reduced, thus leading to a smaller N/C ratio and a higher optical bandgap. In conclusion, a-CN thin-films with adjustable optical bandgaps can be deposited by ECR-CVD. It indicated this novel material have great potential for applications in optoelectronic devices.
Kang, Jung-Hyun. "Epitaxial growth and characterisation of GaAs nanowires on Si for optoelectronic device applications." Phd thesis, 2012. http://hdl.handle.net/1885/149685.
Повний текст джерелаRamesh, Vidya. "Growth and characterisation of InP-based core-shell nanowires for optoelectronic device applications." Master's thesis, 2011. http://hdl.handle.net/1885/149902.
Повний текст джерелаJiang, Nian. "Growth and Characterisation of GaAs/AlGaAs Core-shell Nanowires for Optoelectronic Device Applications." Phd thesis, 2015. http://hdl.handle.net/1885/104572.
Повний текст джерелаBhardwaj, Devanshi. "Vanadium Dioxide: Bulk and Thin Films for Device Applications." Thesis, 2020. https://etd.iisc.ac.in/handle/2005/4758.
Повний текст джерела"Sensors and Their Applications for Connected Health and Environment." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.51613.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Chemical Engineering 2018
NAGPAL, DIVYANSHI, and TANISHA BHADAURIA. "STRUCTURAL AND SPECTROSCOPIC STUDIES OF Eu3+ ACTIVATED POTASSIUM BISMUTH MOLYBDATE PHOSPHOR FOR OPTOELECTRONIC DEVICE APPLICATIONS." Thesis, 2022. http://dspace.dtu.ac.in:8080/jspui/handle/repository/19491.
Повний текст джерелаChih-ChiangYang and 楊智強. "Metal-Modified ZnO Nanostructures Grown by Low-Temperature Hydrothermal Method for Optoelectronic Device Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/4wt2f6.
Повний текст джерела國立成功大學
微電子工程研究所
104
In this dissertation, the metal-modified ZnO nanostructures were grown on an a-ZnO seed layer via the low-temperature hydrothermal method (90 °C) and applied to metal semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) and field emission devices. This dissertation is divided into three parts. In the first part, Ga-doped ZnO nanosheet-based (MSM) ultraviolet (UV) photodetectors are investigated and Ga-doped ZnO nanorods (NRs) with different Ga concentrations are synthesized for application to an MSM UV PD. In the second part, the synthesis of Ag nanoparticle (NP)-decorated ZnO NR MSM UV PDs is discussed. Finally, the third part discusses the synthesis of Ag NP-decorated ZnO NR field emitters under UV illumination. The beginning of this dissertation is divided into two sections. First, vertical Ga-doped ZnO nanosheets are synthesized on a ZnO-seeded glass substrate via the hydrothermal method at low temperature and used to fabricate a GZO NS MSM UV PD. The average length and average diameter of the interwoven GZO nanosheet was 720 and 26 nm. The measured cutoff wavelength of the PDs was 340 nm when biased at 1 V, and the measured fabricated PD responsivity was 2.85 × 10-5. The corresponding UV-to-visible rejection ratio was approximately 81 when biased at 1 V. The noise equivalent power (NEP) of the fabricated GZO NS MSM PD was 5.92 × 10-9 W, and its specific detectivity was 2.24 × 109 cm • Hz0.5 • W-1. The fabrication of ZnO NRs doped with various Ga concentrations on a ZnO-seed layer/glass substrate via the low temperature hydrothermal method is then presented. Ga-doped ZnO (GZO) NR-based UV PDs were fabricated under a bias of 1 V. The measured device responsitivities of the ZnO NRs doped with 0.25, 0.5, and 1 mM Ga were 2.2 × 10−2, 14.9, and 14.1 A/W, respectively. Varying the Ga concentration allowed control of the responsivity of the fabricated PDs. Under a bandwidth of 1 kHz and applied bias of 1 V, the NEP of the GZO NR PDs with 0.25, 0.5, and 1 mM Ga were 1.06 × 10−9, 3.13 × 10−11, and 1.29 × 10−10 W, respectively, and their corresponding detectivities were 1.24 × 1010, 4.21 × 1011 W, and 1.01 × 1011 cm•Hz0.5•W−1. In the second part of this dissertation, Ag NP-decorated ZnO NR arrays were synthesized on a ZnO-seeded glass substrate using a novel and simple hydrothermal method. Under an applied bias of 0.2 V and incident light wavelength of 380 nm, a UV PD based on the Ag NP-decorated ZnO NRs showed a high responsivity of 12.4 A W with a corresponding UV-to-visible rejection ratio of 4478. The noise spectrum of the UV PD was obtained using pure 1/f noise, and the NEP of the fabricated Ag NP-decorated ZnO NR MSM PD was found to be 4.85 × 10−11 W; a detectivity of 2.72 × 1011 cm·Hz0.5·W−1 was also observed. Finally, Ag NP-decorated ZnO NRs were successfully synthesized on a glass substrate via the hydrothermal method at a low temperature of 90 °C and used to fabricate Ag NP-decorated ZnO NR field emission devices. The resulting Ag NP-decorated ZnO NRs of ultra-turn-on field was reduced to approximately 3.93 and 2.04 V/μm in the dark and under UV illumination, respectively, and the corresponding field enhancement factors were 1,593 and 57,872. These results indicate that the enhanced FE of Ag NP-decorated ZnO NRs can be attributed to the effective formation of potential wells on the surfaces of the Ag NPs, which collect electrons by field emission from the Ag NPs to the vacuum level to enhance field emission.
Wu, Fan-Lei, and 吳凡磊. "Technologies of Epitaxial Lift-Off Process and Reused GaAs Substrate for Optoelectronic Device Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/40568191288014695026.
Повний текст джерела國立中興大學
精密工程學系所
104
In this dissertation, two important techniques were respectively demonstrated for the development of optoelectronic devices. In the first part, the characteristics of different etching solutions applied to the epitaxial lift-off process (ELO) for separating the epitaxial layer from GaAs substrate were explored in detail. These etching solutions included the hydrofluoric acid (HF) solution and the hydrophilic solutions, such as HF:acetone, HF:isopropanol, HF:methanol. In lateral etching the AlAs sacrificial layer, the mixed solutions all displayed higher lateral etching rates ranging between 7.4 and 14.3 μm/min than pure HF solution (3.6 μm/min). Among these mixed solutions, although the HF:acetone solution had medium surface tension and contact angle, it was still exhibited the highest lateral etching rate (14.3 μm/min). Additionally, it was worthy to note that the sample surface had few by-products as compared with other solutions while using HF:acetone solution. This indicated that the reaction bubble vent possessed few obstacles during the etching reaction for avoiding reducing the reaction rate. Furthermore, it was found that using HF:acetone solution nearly prevented from degradation of the cell efficiency after the ELO process. As concerning the reuse times of GaAs substrate, indium and phosphorous can remain on the reused GaAs substrate surface via diffusing from the epilayers. These residues can result in the degradation of subsequent epilayer quality. An additional wet etching process, which used NH4OH:H2O2:H2O2, can not only remove the residues but also decrease the surface roughness of reused GaAs substrate. Moreover, the surface roughness of reused GaAs substrate can be further improved by annealing at 650oC in arsine and hydrogen atmosphere with 30 minutes. A GaAs-based solar cell was successfully achieved on the four-times reused GaAs substrate which was fabricated by ELO process and two optimized methods mentioned above. The efficiency of solar cell was enhanced to 1.68 times. It confirmed that the NH4OH:H2O2:H2O2 etching and annealing processes benefited to the reliability and reused times of GaAs substrate. For exploring the possibility of applying ELO process to LED devices (ELO-LED), the thin-film vertical-type AlGaInP LED on Cu substrate was fabricated by using ELO process to transfer the substrate from GaAs to Cu substrate. Cu substrates with various patterns were designed in order to prevent the crack formation in the epilayer during the ELO process. The stress distribution in the LED during the ELO process was simulated by the finite element method. The Cu substrate with an optimum pattern which can confine the maximum stress to the chip edges and significantly reduce stress process was obtained based on the simulation results. This Cu substrate could avoid generating cracks after separating the GaAs substrate. In addition, the chemical etching process was regularly used to remove the GaAs substrate and then transfer to Cu substrate in the LED device process (CE-LED). To compare the two different substrate removal methods (ELO-LED and CE-LED), the forward voltages (@350 mA) of the CE-LED and ELO-LED were 2.20 and 2.29 V, and the output powers (@350 mA) were 49.9 and 48.2 mW, respectively. Furthermore, the surface temperatures (@350 mA) of these two samples were 46.9-48.3 and 45.2-47.0oC, respectively. Obviously, the device characteristics of the ELO-LED were very similar to the CE-LED. It confirmed that the design of optimum patterned Cu substrate was very helpful to obtain the thin-film vertical-type AlGaInP LEDs. This also implied that the ELO technique can effectively be applied to the optoelectronic devices, reducing the cost. The second part in the thesis focused on the effect of various buffer layers on the efficiency of InGaAs solar cells. Three different buffer layers on solar cells including low-temperature buffer layer (2S-cell), step-graded layer (S-cell), and linear-graded layer (L-cell) were fabricated. Dislocation defects only obviously exited in these buffer layers by the transmission electron microscopy (TEM) observation. Therefore, these dislocation defects can significantly suppress the extension up to the active In0.16Ga0.84As layer. Furthermore, the In0.16Ga0.84As epilayer of L-cell exhibited the lowest defect density, residual stress, carrier recombination rate. The efficiency of the 2S-cell, S-cell and L-cell were 9.8%, 14.4%, 16.1%, respectively. Summarized above results, the L-cell of employing the InxGa1-xAs linear-graded buffer layer can achieve good epilayer quality and high cell efficiency. In addition, various angles ranging from 0° to 90° for the stripe-shaped front electrode were designed on the L-cell. When the front electrode angles were fixed at 0° and 90°, the devices possessed high conversion efficiencies of 16.34% and 16.58%, respectively. This was attributed to the change of the transport path of the carriers, inducing that the carriers can be avoided confining the dislocations.
"Pulsed Laser Deposition of Highly Conductive Transparent Ga-doped ZnO for Optoelectronic Device Applications." Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.8868.
Повний текст джерелаDissertation/Thesis
Ph.D. Materials Science and Engineering 2011
"Material Properties of MBE Grown ZnTe, GaSb and Their Heterostructures for Optoelectronic Device Applications." Doctoral diss., 2012. http://hdl.handle.net/2286/R.I.15804.
Повний текст джерелаDissertation/Thesis
Ph.D. Physics 2012
Lin, Yu-Hsiang, and 林裕翔. "Study of 2-D and 3-D Nanosphere Lithographyfor Optoelectronic Device and Sensor Applications." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/31610052764531936539.
Повний текст джерела臺灣大學
材料科學與工程學研究所
95
Nanosphere lithography (NSL) is a novel method for the fabrication of hexagonal close-packed structures by self-assembly monolayer nanosphere array on flat substrates. Here the monolayer nanospheres are taked as etching mask layer like patterned resists. Furthermore, the period and dimension can be controlled by the size of nanospheres. Because of cheap, rapid, and extensive applications, it’s one of the important nanofabrication techniques. In the fabrication of monolayer nanosphere array, we fabricate large-area monolayer nanospheres by spin coating method and using as etching mask for the fabrication of sub-wavelength pyramid anti-reflection structure on silicon substrate by wet etching and dry etching processes. And the reflectance of silicon substrates can be reduced to 3%. Besides, we fabricate periodical metal hole-arrays which have high surface plasma transmission by deposition and lift-off processes on monolayer nanospheres. And in three-dimensional (3D) opal-like photonic crystal, we investigate the influence of different environments and nanospheres with different surface charge distribution on opal structures. Besides, we provide a rapid fabrication method of fabricating silica inverse opal structure. And we try to infiltrate gold nanoparticles (Au NPs) into inverse opal. It’s hard to catch Au NPs in 3D nano structure without aggregation, but we find the optimal parameter to fabricate inverse opal structure with adhered Au NPs uniformly. This photonic crystal have both photonic band gap(PBG) and localized surface plasma resonance (LSPR) effects, and the two properties in one structure can be used to probe the refractive index of infiltrated solution and the properties of bio-molecular which adhered on Au NPs. At last, we use drop coating method to add organic luminescence material on opal and find the luminescence wavelength at photonic band gap is confined by opal structures. When the detector angle is changed, the confined luminescence wavelength of opal which added organic luminescence material is also changed. Besides, the emission intensity can be enhanced by energy transfer of polystyrene and large surface area.