Download or read book Development of New Building Blocks for Constructing Novel Polymer Semiconductors for Organic Thin Film Transistors written by Zhuangqing Yan and published by . This book was released on 2013 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic semiconductors are envisioned to have widespread applications in flexible displays, radio-frequency identification (RFID) tags, bio- and chem-sensors, as well as organic solar cells. Polymer semiconductors are particularly suitable for the low-cost manufacture of organic electronics using printing techniques due to their excellent solution processability and mechanical properties. This work focuses on the development of two novel building blocks, IBDF and DTA, which can be used for the construction of high performance organic thin film transistors (OTFTs) and organic photovoltaics (OPVs). Two copolymers, P6-IBDF-T and P5-IBDF-T, and a homopolymer P6-IBDF were prepared using the IBDF building block. Copolymer P6-IBDF-T has been prepared via the Stille-coupling polymerization. This polymer exhibits a small band gap of 1.36 eV with HOMO/LUMO energy level of -5.69 eV/-4.43 eV. P6-IBDF-T showed stable electron transport performance in encapsulated thin film transistors and ambipolar transport performance in non-encapsulated TFTs. Balanced hole/electron mobilities of up to 8.2 ×10-3/1.0 ×10-2 cm2V-1s-1 was achieved in bottom-contact, bottom-gate organic thin film transistors. In addition, the broad absorption of the polymer over the UV-Vis range suggested that this polymer is suitable for applications in solar cells. The effect of conjugation on mobility and UV-vis spectra of the polymer was studied by comparing P5-IBDF-T with P6-IBDF-T. The ideal of indirect electron transition was proposed to explain the difference between UV-Vis light absorption spectra for these two polymers. DTA building block was used to construct four D-A copolymers, namely PDTA-T, PDTA-BT, PDAT-BTV, and PDTA-TT. These polymers were characterized by UV-Vis, CV, DSC, TGA, AFM and XRD. Device performance was also investigated on OTFTs. The device performance of DTA based polymer increased as the area of electron donor increase from T in PDTA-T to BTV in PDTA-BTV. PDTA-BTV exhibits hole mobility of 1.3×10-3 cm2 V-1 s-1 with Ion/Ioff value of ~103-4 in bottom-contact, bottom-gate organic thin film transistors. All DTA based copolymers exhibited small optical bandgaps (1.18 - 1.27 eV) and required none or moderate thermal treatment during fabrication process. These make them promising candidates for cost-effective OPV applications.

Download or read book Synthesis and Performance Characterization of Polymer Semiconductors for Organic Thin Film Transistors written by Chang Guo and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As the most promising semiconductor candidates for organic thin film transistors (OTFTs), donor-acceptor (D-A) type [pi]-conjugated polymers have received much attention in the recent years. Their excellent printability, light weight, mechanical robustness and flexibility are desirable characteristics for low cost and portable electronics. Some issues of polymer semiconductors as such relatively low charge carrier mobility compared to that of silicon as well as the poor stability during manufacturing and device operation in an ambient environment still remain. Although extensive efforts have been made to develop electron acceptor building blocks, which are considered to be critical for achieving high mobility, very few electron acceptors for constructing novel high performance D-A polymers are available. Nowadays most D-A polymers were synthesized using traditional Suzuki or Stille coupling, which use boron- or tin-containing monomers that require extra synthetic steps and are highly toxic in some cases (such as organotin monomers). As an alternative method, the direct (hetero)arylation polymerization (DHAP), provides a new approach to constructing D-A polymers in a cost-effective and environment friendly manner. Certain polymers synthesized by DHAP have demonstrated similar or even better performance compared to the polymers made by other methods. However side reactions and limitations on the types of monomers for DHAP have been reported. To bring the OTFT performance of polymer semiconductors to the next level, new acceptor building blocks and a further study of DHAP need to be exploded. In the first part of this thesis (Chapters 2-4), a novel electron acceptor building block, indigo is chosen, considering its electron deficiency property, highly coplanar geometry and ease of synthesis. Furthermore, indigo and its small molecule derivatives have been demonstrated to be promising semiconductors in OTFTs. However, indigo-containing polymer semiconductors have not been reported yet. In this study, we used 6,6'-indigo as an electron acceptor to successfully develop several n-type electron transport semiconductors. Surprisingly, when 5,5'-indigo was used, the opposite p-type hole transport performance was observed. To the best of our knowledge, this is the first observation that the charge transport polarity could be controlled or switched through different regiochemical connections of a building block. The second part of this thesis (Chapters 5 and 6) focuses on the optimization and development of dipyrrolopyrrole (DPP) based polymers. In Chapter 5, DHAP is used to construct a novel high performance pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (1,4-DPP)-thiazole based polymer. Two synthetic routes are compared and discussed, and the polymer synthesized under optimized DHAP conditions showed better performance than that of a similar polymer obtained by Stille coupling. In Chapter 6, pyrrolo[3,4-c]pyrrole-1,3(2H,5H)-dione (1,3-DPP), an isomer of 1,4-DPP, is developed for constructing polymer semiconductors with promising performance in OTFTs. Systematic studies on the synthesis of these new acceptor building blocks as well as the exploration of DHAP have provided insights into the structure-property relationships of novel D-A polymers and may lead to the discovery of the next generation high mobility polymer semiconductors.

Download or read book Development of New Nanostructurally Engineered Polymer Semiconductors for Organic Electronics written by Amani Alsam and published by . This book was released on 2014 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this thesis was focused on organic semiconductors and has resulted in the development of novel printable polymer semiconductors that can be used in organic thin film transistors (OTFTs) and organic photovoltaics (OPVs), or solar cells. Polymers used in OTFT applications must have particular characteristics, such as a highly ordered or crystalline structure, favoured molecular orientation, and appropriate energy levels for either hole transport (p-type semiconductors) or electron transport (n-type semiconductors). Achieving these properties requires control of the design and synthesis of the polymers through the choice of appropriate building blocks and side chain substituents. In contrast, for OPV applications, the band gap, thin film morphology, and balance of the donor's hole mobility and the acceptor's electron mobility must be finely tuned for optimal photovoltaic performance. The specific focus of the research was on a new type of donor-acceptor copolymers that have alternating electron-accepting azo units and common electron donor units (e.g., thiophene). These polymers are expected to have strong intermolecular interactions due to the donor-acceptor effect, which could lead to improved molecular organization for efficient charge carrier transport in OTFT devices. The donor-acceptor effect also creates narrow band gap polymers, which are preferred for optimum light harvesting. The polymer materials developed in this research are evaluated as channel semiconductors in OTFTs and can also be used as donors in polymer solar cells. Zs discovery of which complemented previous work conducted by the same research group. These innovative building blocks would be valuable in numerous applications, including OTFTs and OPVs. Five polymers have been created, three of which show the most promising potential for OTFT and OPV applications: P1-DTA-BTV, P5-DTAE-BT, and P6-DTAE-TT. All of these copolymers have been synthesized via Stille coupling reaction. The first copolymer, P1-DTA-BTV, which exhibits a small band gap of 1.13 eV, with HOMO and LUMO energy levels of -5.21 eV and - 4.08 eV, respectively, is suitable for both OTFT devices and OPV applications. P5-DTAE-BT and P6-DTAE-TT, on the other hand, are characterized by broader band gaps of 1.29 eV and 1.32 eV, respectively, and their average HOMO and LUMO energy levels are -5.43 eV, -4.20 eV, and -5.40 eV, -4.00 eV, respectively. It has been experimentally demonstrated that the presence of an ester group in the (E)-1,2-di(thiazol-2-yl)diazene DTA monomer helps lower the LUMO energy level, creating the broad band gap revealed in the (E)-bis(2-octyldodecyl) 2,2'-(diazene-1,2-diyl)bis(thiazole-4-carboxylate) DTAE copolymer results, and making the P5-DTAE-BT D-A copolymer an n-type semiconductor, which is very useful for the applications mentioned above. The polymers were characterized by Differential Scanning Calorimetry DSC, Thermal Gravimetric Analysis TGA, Ultraviolet-Visible Spectrometry UV-Vis, Cyclic Voltammetry CV, Atomic Force Microscopy AFM, X-Ray Diffraction XRD.

Download or read book Large Area and Flexible Electronics written by Mario Caironi and published by John Wiley & Sons. This book was released on 2015-01-13 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: From materials to applications, this ready reference covers the entire value chain from fundamentals via processing right up to devices, presenting different approaches to large-area electronics, thus enabling readers to compare materials, properties and performance. Divided into two parts, the first focuses on the materials used for the electronic functionality, covering organic and inorganic semiconductors, including vacuum and solution-processed metal-oxide semiconductors, nanomembranes and nanocrystals, as well as conductors and insulators. The second part reviews the devices and applications of large-area electronics, including flexible and ultra-high-resolution displays, light-emitting transistors, organic and inorganic photovoltaics, large-area imagers and sensors, non-volatile memories and radio-frequency identification tags. With its academic and industrial viewpoints, this volume provides in-depth knowledge for experienced researchers while also serving as a first-stop resource for those entering the field.

Download or read book Organic Thermoelectric Materials written by Zhiqun Lin and published by Royal Society of Chemistry. This book was released on 2019-10-18 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarises the significant progress made in organic thermoelectric materials, focusing on effective routes to minimize thermal conductivity and maximize power factor.

Download or read book Optoelectronic Organic Inorganic Semiconductor Heterojunctions written by Ye Zhou and published by CRC Press. This book was released on 2021-01-20 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optoelectronic Organic-Inorganic Semiconductor Heterojunctions summarizes advances in the development of organic-inorganic semiconductor heterojunctions, points out challenges and possible solutions for material/device design, and evaluates prospects for commercial applications. Introduces the concept and basic mechanism of semiconductor heterojunctions Describes a series of organic-inorganic semiconductor heterojunctions with desirable electrical and optical properties for optoelectronic devices Discusses typical devices such as solar cells, photo-detectors, and optoelectronic memories Outlines the materials and device challenges as well as possible strategies to promote the commercial translation of semiconductor heterojunctions-based optoelectronic devices Aimed at graduate students and researchers working in solid-state materials and electronics, this book offers a comprehensive yet accessible view of the state of the art and future directions.

Download or read book High performance Polymer Semiconductors for Organic Thin film Transistors written by Sun Bin and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel polymer semiconductor with side chains thermally cleavable at a low temperature of 200 °C was synthesized. The complete cleavage and removal of the insulating 2-octyldodecanoyl side chains were verified with TGA, FT-IR, and NMR data. The N-H groups on the native polymer backbone are expected to form intermolecular hydrogen bonds with the C=O groups on the neighboring polymer chains to establish 3-D charge transport networks. The resulting side chain-free conjugated polymer is proven to be an active p-type semiconductor material for organic thin film transistors (OTFTs), exhibiting hole mobility of up to 0.078 cm2V-1s-1. This thermo-cleavable polymer was blended with PDQT to form films that showed a higher performance than the pure individual polymers in OTFTs. MoO3 or NPB was used as a hole injection buffer layer between the metal electrodes and the polymer semiconductor film layer in OTFT devices. This buffer layer improved hole injection, while its use in the OTFT, improved the field-effect mobility significantly due to better matched energy levels between the electrodes and the polymer semiconductor.

Download or read book Non conventional Building Blocks for Organic Electronics written by Panikki Chandima Bulumulla and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic semiconductors are potential candidates for replacing high-cost silicon electronics for low-end applications where high mobilities are not required. Owing to unique advantages such as solution processability, flexibility, lightweight, low cost with countless structural modifications, organic semiconductors can be realized for many applications using high throughput roll-to-roll fabrication techniques. Hence, a remarkable amount of scientific efforts have been dedicated to improving electronic and physical properties of these materials. Throughout the past two decades, many improvements in the field have been achieved by designing novel building blocks. Since efficiencies and mobilities in organic solar cells and transistors have stagnated, it is highly desirable to seek and develop non-conventional building blocks for organic electronics. In this dissertation, the fundamentals and recent developments of non-conventional materials are covered in Chapter 1. Operation principles, charge transport of organic field effect transistors and organic photovoltaics are introduced. Compared to conventional thiophene-based -electron donor materials, promising non-conventional pyrrole based donor materials employed in organic electronics are discussed and summarized. Similarly, non-conventional electron acceptors could be used to fabricate organic solar cells. By using inorganic semiconducting quantum dots (QDs), organic-inorganic hybrid solar cells could be fabricated. Different systems with polymer: QD solar cells are also discussed and summarized in chapter 1. Chapter 2 describes the effect on organic field effect transistor (OFET) properties of two novel small molecules containing terminal N-dodecylthieno[3,2-b]pyrrole (TP) donors and N-dodecylfuro[3,2-b]pyrrole (FP) donors with a central thiophene flanked 5,6-difluorobenzo[c][1,2,5]thiadiazole (FBT) acceptor. The influence on frontier molecular orbital energy levels, UV-vis absorption, electrochemical properties, OFET parameters and morphological effects were investigated. In chapter 3, the effect of flanking group on banana shape small molecules is discussed by using terminal N-dodecylthieno[3,2-b]pyrrole (TP) donors, and thiophene or furan flanked benzo[c][1,2,5]thiadiazole (BT) central units. Upon changing similar flanking groups, the curvature of the small molecules was changed. Thiophene flanked small molecule showed high hole mobility of 0.08 cm2 /V s while furan flanked small molecule performs poorly due to both heteroatom effect and the degree of curvature. Chapter 4 describes the extension of thieno[3,2-b]pyrrole based small molecules to polymers. A Novel conjugated polymer is synthesized by copolymerizing N-methylthieno[3,2-b]pyrrole and 2,5-bis(2-octyldodecyl)-3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP) via Stille coupling polymerization. With an optimized molecular weight, the polymer exhibited high hole mobility of 0.12 cm2 /V s in OFET devices. The high hole mobility reflects the potential of the thieno[3,2-b]pyrrole building block. Inorganic QDs also can be employed as electron acceptors compared to conventional fullerene derivatives in bulk heterojunction (BHJ) solar cells. However, they do not outperform conventional fullerene counterparts. Therefore in chapter 5, a facile method is described to generate thiol functionalized block copolymers to improve the interaction between photoactive polymers and QDs. By incorporating only 17 mol% of the thiol containing block a two-fold increase in power conversion efficiency was observed. The improved interaction was supported by atomic force microscopy and photoluminescence quenching studies.

Download or read book Creating New Building Blocks for Organic Electronics written by Qian Miao and published by . This book was released on 2005 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nature inspired Polymers written by Jesse Thomas Ernest Quinn and published by . This book was released on 2018 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of an organic thin film transistor was first introduced in the late 1980s and research was directed toward two key merits of performance, field-effect mobility and current ON/OFF ratio. Today these two key merits of performance are still highly sought after; however, a shortcoming associated with most organic semiconductors is their susceptibility to chemical interactions and photo-excitation; to name but a few of their caveats. Consequently, the development of organic semiconductors with high charge carrier transport as well as good air stability is still desired. Nature provides a vast diversity of materials and looking for natural or nature inspired semiconductors appears to be a promising route towards interesting and pertinent materials. Organic thin film transistors based on natural or natural-inspired semiconductors such as indigo, -carotene, indanthrene, and perylene diimide have demonstrated good charge carrier transport and some cases demonstrated equally good stability in ambient conditions. In this work, a number of moderately to excellent air stable polymeric semiconductors were designed and synthesized that were nature inspired. Chapter 3 describes the synthetic account and elaborates on a broad spectrum of properties pertaining to the novel fluorene-fused triphenodioxazine based polymer (PFTPDOBT). PFTPDOBT exhibited excellent charge transport performance in ambient conditions reaching hole mobilities as high as ~10^-2 cm^2 V^-1 s^-1 and modest hole mobilities in water-gated transistors (~10^-3 cm^2 V^-1 s^-1). In Chapter 4, a series of pyrazino[2,3-g]quinoxaline-2,7-dione (PQx) based polymers were developed and characterized. These PQx based polymers displayed exciting UV-Vis-NIR spectra when in the presence of an organic acid or Lewis acid. Their electrical characteristics in OTFTs were typical of ambipolar charge transport. Hole mobilities reached as high as ~10^-2 cm^2 V^-1 s^-1 with corresponding electron mobilities as high as ~10^-3 cm^2 V^-1 s^-1. Lastly, Chapter 5 gives accounts on significant research pertaining to novel polymeric semiconductors based on the pyrimido[4,5-g]quinazoline-4,9-dione (PQ) moiety. A systematic study of PQ-based polymeric semiconductors is presented in both nitrogen, ambient, and aqueous environments. Typical hole charge transport was obtained between ~10^-2 and ~10^-3 cm^2 V^-1 s^-1. Both PPQ2T-BT-24 and PPQ2T-TT-24 demonstrated moderate to excellent stability in these environments. To exploit the photo-excitation of organic semiconductors, a series of PQ-based polymeric semiconductors were incorporated in phototransistors and also blended with PC61BM. The PPQ2T-BT-24:PC61BM blend reached ultrafast response times as low as 1 ms for rise and 8 ms for fall with photoresponsivity as high as 0.88% and EQE of 189%. Lastly, PPQ2T-BT-24 and PPQ2T-TT-24 were incorporated into OTFT gas sensors where they demonstrated low detection limits with fast recovery times for a particular analyte.

Download or read book Molecular Engineering of Polymer Semiconductors for Electronics and Photonics written by Ye-Jin Hwang and published by . This book was released on 2015 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been tremendous progress in the development of conjugated polymer semiconductors in the last two decades for diverse applications in organic electronics and photonics. Most notably, advances in p-type (hole-conducting) polymers have enabled the development of high-performance organic field-effect transistors (OFETs) as well as more efficient fullerene-based organic photovoltaics (OPVs). In contrast, n-type (electron-conducting) polymer semiconductors remain relatively scarce and consequently the performance of n-channel OFETs and all-polymer solar cells has lagged far behind p-channel OFETs and fullerene-based OPVs. This dissertation mainly focuses on the design and synthesis of new n-type polymer semiconductors for device applications in n-channel OFETs and non-fullerene OPVs. It aims to achieve better understanding of the relationships between molecular structure, processing, morphology, and device performance. New n-type polymer semiconductors were developed based on strong electron withdrawing naphthalene diimide (NDI) building block with various selenophene derivatives as co-monomers. The resulting highly crystalline poly(naphthalene diimide)s (PNDIs) gave the electron mobility as high as 0.24 cm2/Vs in n-channel OFET measurements in air which is comparable or even higher mobility compared to most of the p-channel transistors. Using NDI-selenophene copolymer, PNDIS-HD, as acceptor, a photovoltaic performance with a power conversion efficiency (PCE) of 3.3 % (Jsc = 7.78 mA/cm2, Voc = 0.76 V, FF = 0.55) was achieved in all-polymer solar cells, and this work has stimulated a lot of current interest in fullerene-free OPVs. In further studies in all-polymer solar cells, highly enhanced photovoltaic performance was achieved by chemical modifications of acceptor polymers and controlling self-organization kinetics of polymer/polymer blend films. From these studies, a critical role of the bulk crystallinity of acceptor polymer was revealed, and provided an important criterion for the molecular design of high performance polymer acceptors. Furthermore, all-polymer solar cells with more favorable bulk morphology by slow self-organization of polymers facilitated by room temperature film aging resulted in enhanced charge carrier mobility and photocurrent. Resulting all-polymer solar cells with PCE over 7 % showed a great potential of non-fullerene solar cells and demonstrated for the first time a viable alternative pathway to organic photovoltaics.

Download or read book Solution Processable Organic Semiconducting Materials for Thin Film Transistors and Photovoltaic Applications written by Sang-wŏn Ko and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic transistors and solar cells offer the potential advantages of low-cost, large-scale fabrication by solution processing techniques, and compatibility with both flexible and lightweight plastic substrates. Continuous development of new organic materials has improved their performance, thus enabling the commercialization of these conducting polymers in recent years. However, understanding the relationship between polymer packing structures and mobilities is still lacking. Furthermore, to enable a polymer to serve as an effective donor material in bulk heterojunction (BHJ) solar cells, several important properties have to be considered, such as band gap, absorption coefficient, effective charge transport, and a relatively deep HOMO. Needless to say, careful balancing of these properties remains challenging. Thus, this thesis aims to gain a better understanding of materials design rules to address the above issues using two types of conjugated polymers. First, new donor-acceptor copolymers were designed and synthesized to gain insights into designing efficient donor materials in BHJ solar cells. Second, poly(3,4-disubstituted thiophene) derivatives were designed and synthesized to study relationships between structural design, packing, charge transport property, and solar cell performance. In the first part of my thesis, I have prepared vinylene linked co-polymers in order to achieve low bandgap polymers by extending [Pi]-conjugation lengths. I found that the hole mobilities of the polymers scaled with the molecular weights in these amorphous polymers. Optical absorption at longer wavelengths was improved by eliminating torsions along the polymer backbones. Current density (Jsc) in BHJ solar cells depended on the overall intensity of absorption and hole mobility of donor materials. Comparing to the amorphous vinylene linked co-polymers, charge carrier mobility could be enhanced by employing thienopyrazine based co-polymers, which contain rigid fused aromatic rings promoting well ordered inter-chain packing. Removing of the adjacent thiophene groups around the thienopyrazine acceptor core markedly increased the optical absorption of the polymer and raised its ionization potential, resulting in power conversion efficiency (PCE) of 1.57%. This investigation on the new co-polymers could provide a useful guideline for designing efficient donors for BHJ solar cells. In the second part of my thesis, I designed and synthesized polythiophene derivatives to understand structure-property relationships in detail. Despite their slightly larger band gaps, polythiophene derivatives are nonetheless important active materials due to their high absorption coefficients and high charge transport mobilities. Furthermore, their facile synthesis and ease of structural modifications with various substituents are the advantages of using polythiophene derivatives as model conjugated polymer systems. To examine the influence of backbone twisting on performance of transistors and BHJ solar cells, I systematically imposed twists within the conjugated backbones of poly(3,4-disubtituted thiophene (P34AT) using a unsubstituted thiophene spacer of varying sizes. When a moderate twist was introduced to the P34AT backbone, a 19% enhancement in the open-circuit voltage vs. poly(3-hexylthiopene) based devices and high PCE (4.2%) were achieved without sacrificing the short-circuit current density and the fill factor. Despite the high charge transport mobility (0.17 cm2/Vs), P34AT hardly showed [Pi]-[Pi] stacking in X-ray diffraction, suggesting that a strong [Pi]-[Pi] stacking is not always necessary for high charge carrier mobility; in which other potential polymer packing motifs (in addition to the edge-on structure) can lead to a high device performance. To gain further knowledge in structure-property relationships of the less explored 3,4-disubstituted polythiophene system, various P34AT derivatives were prepared and their opto-electronic property, packing structure, and device performance were studied. Among P34AT derivatives containing fused thiophene rings, a higher PCE was achieved with a benzodithiophene based polymer (PDHBDT) having a larger absorption coefficient, higher hole mobility, and deeper HOMO. The PDHBDT also exhibited a thermotropic phase transition behavior, leading to mobility up to 0.46 cm2/Vs where the polymer backbones adapt an edge-on lamellar packing structure. In the last part of this thesis, low band gap P34AT derivatives, which incorporate electron withdrawing groups, were prepared to improve photocurrent. However, I observed that a low absorption coefficient and a low hole mobility limited current density in solar cells. Thus, this indicates that low band gap polymers with strong absorption properties and good charge transports are critical towards molecular design for achieving high PCE. Collectively, through rational design and characterization of these novel polymers, this thesis has illustrated that better understanding of molecular design rules for engineering opto-electronic properties and packing behavior, will lead to higher device performance.

Download or read book Handbook of Visual Display Technology written by Janglin Chen and published by Springer. This book was released on 2012-01-23 with total page 2700 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook offers a comprehensive description of the science, technology, economic and human interface factors associated with the displays industry. With expert contributions from over 150 international display professionals and academic researchers, it covers all classes of display device and discusses established principles, emergent technologies, and particular areas of application.

Download or read book Beyond the Molecular Frontier written by National Research Council and published by National Academies Press. This book was released on 2003-03-19 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemistry and chemical engineering have changed significantly in the last decade. They have broadened their scopeâ€"into biology, nanotechnology, materials science, computation, and advanced methods of process systems engineering and controlâ€"so much that the programs in most chemistry and chemical engineering departments now barely resemble the classical notion of chemistry. Beyond the Molecular Frontier brings together research, discovery, and invention across the entire spectrum of the chemical sciencesâ€"from fundamental, molecular-level chemistry to large-scale chemical processing technology. This reflects the way the field has evolved, the synergy at universities between research and education in chemistry and chemical engineering, and the way chemists and chemical engineers work together in industry. The astonishing developments in science and engineering during the 20th century have made it possible to dream of new goals that might previously have been considered unthinkable. This book identifies the key opportunities and challenges for the chemical sciences, from basic research to societal needs and from terrorism defense to environmental protection, and it looks at the ways in which chemists and chemical engineers can work together to contribute to an improved future.

Download or read book Introduction to Thin Film Transistors written by S.D. Brotherton and published by Springer Science & Business Media. This book was released on 2013-04-16 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Thin Film Transistors reviews the operation, application and technology of the main classes of thin film transistor (TFT) of current interest for large area electronics. The TFT materials covered include hydrogenated amorphous silicon (a-Si:H), poly-crystalline silicon (poly-Si), transparent amorphous oxide semiconductors (AOS), and organic semiconductors. The large scale manufacturing of a-Si:H TFTs forms the basis of the active matrix flat panel display industry. Poly-Si TFTs facilitate the integration of electronic circuits into portable active matrix liquid crystal displays, and are increasingly used in active matrix organic light emitting diode (AMOLED) displays for smart phones. The recently developed AOS TFTs are seen as an alternative option to poly-Si and a-Si:H for AMOLED TV and large AMLCD TV applications, respectively. The organic TFTs are regarded as a cost effective route into flexible electronics. As well as treating the highly divergent preparation and properties of these materials, the physics of the devices fabricated from them is also covered, with emphasis on performance features such as carrier mobility limitations, leakage currents and instability mechanisms. The thin film transistors implemented with these materials are the conventional, insulated gate field effect transistors, and a further chapter describes a new thin film transistor structure: the source gated transistor, SGT. The driving force behind much of the development of TFTs has been their application to AMLCDs, and there is a chapter dealing with the operation of these displays, as well as of AMOLED and electrophoretic displays. A discussion of TFT and pixel layout issues is also included. For students and new-comers to the field, introductory chapters deal with basic semiconductor surface physics, and with classical MOSFET operation. These topics are handled analytically, so that the underlying device physics is clearly revealed. These treatments are then used as a reference point, from which the impact of additional band-gap states on TFT behaviour can be readily appreciated. This reference book, covering all the major TFT technologies, will be of interest to a wide range of scientists and engineers in the large area electronics industry. It will also be a broad introduction for research students and other scientists entering the field, as well as providing an accessible and comprehensive overview for undergraduate and postgraduate teaching programmes.

Download or read book Atomic Layer Deposition for Semiconductors written by Cheol Seong Hwang and published by Springer Science & Business Media. This book was released on 2013-10-18 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offering thorough coverage of atomic layer deposition (ALD), this book moves from basic chemistry of ALD and modeling of processes to examine ALD in memory, logic devices and machines. Reviews history, operating principles and ALD processes for each device.