Organic Thin Film Transistor Applications

Text provides information about advanced OTFT (Organic thin film transistor) structures, their modeling and extraction of performance parameters, materials of individual layers, their molecular structures, basics of pi-conjugated semiconducting materials and their properties, OTFT charge transport phenomena and fabrication techniques. It includes applications of OTFTs such as single and dual gate OTFT based inverter circuits along with bootstrap techniques, SRAM cell designs based on different material and circuit configurations, light emitting diodes (LEDs). Besides this, application of dual gate OTFT in the logic gate, shift register, Flip-Flop, counter circuits will be included as well.

Research on organic electronics (or plastic electronics) is driven by the need to create systems that are lightweight, unbreakable, and mechanically flexible. With the remarkable improvement in the performance of organic semiconductor materials during the past few decades, organic electronics appeal to innovative, practical, and broad-impact applications requiring large-area coverage, mechanical flexibility, low-temperature processing, and low cost. Thus, organic electronics appeal to a broad range of electronic devices and products including transistors, diodes, sensors, solar cells, lighting, displays, and electronic identification and tracking devices A number of commercial opportunities have been identified for organic thin film transistors (OTFTs), ranging from flexible displays, electronic paper, radio-frequency identification (RFID) tags, smart cards, to low-cost disposable electronic products, and more are continually being invented as the technology matures. The potential applications for "plastic electronics" are huge but several technological hurdles must be overcome. In many of these applications, transistor serves as a fundamental building block to implement the necessary electronic functionality. Hence, research in organic thin film transistors (OTFTs) or organic field effect transistors (OFETs) is eminently pertinent to the development and realization of organic electronics. This book presents a comprehensive investigation of the production and application of a variety of polymer based transistor devices and circuits. It begins with a detailed overview of Organic Thin Film Transistors (OTFTs) and discusses the various possible fabrication methods reported so far. This is followed by two major sections on the choice, optimization and implementation of the gate dielectric material to be used. Details of the effects of processing on the efficiency of the contacts are then provided. The book concludes with a chapter on the integration of such devices to produce a variety of OTFT based circuits and systems. The key objective is to examine strategies to exploit existing materials and techniques to advance OTFT technology in device performance, device manufacture, and device integration. Finally, the collective knowledge from these investigations facilitates the integration of OTFTs into organic circuits, which is expected to contribute to the development of new generation of all-organic displays for communication devices and other pertinent applications. Overall, a major outcome of this work is that it provides an economical means for organic transistor and circuit integration, by enabling the use of a well-established PECVD infrastructure, while not compromising the performance of electronics. The techniques established here are not limited to use in OTFTs only; the organic semiconductor and SiNx combination can be used in other device structures (e.g., sensors, diodes, photovoltaics). Furthermore, the approach and strategy used for interface optimization can be extended to the development of other materials systems.

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.

Edited and written by the leading researchers and engineers from such companies as Philips, 3M, Xerox, Infineon, PlasticLogic, Eastman Kodak, Dupont, AIXTRON, and Hueck Folien, this book presents unrivalled and undiluted expertise from those who know best how to assess the risks, opportunities and where this technology is really heading. As such, this practical approach complements the more scientific and fundamentals-oriented literature on the market by providing readers with a first-hand insight into industrial activities to commercialize organic electronics. Following an introduction to the topic, including the history, motivation, benefits and potentials, it reviews recent advances and covers all three important facets of organic electronics: the chemical compounds and materials, manufacturing techniques, and the resulting devices together with their current applications.

The remarkable development of organic thin film transistors (OTFTs) has led to their emerging use in active matrix flat-panel displays, radio frequency identification cards, and sensors. Exploring one class of OTFTs, Organic Field-Effect Transistors provides a comprehensive, multidisciplinary survey of the present theory, charge transport studies, synthetic methodology, materials characterization, and current applications of organic field-effect transistors (OFETs). Covering various aspects of OFETs, the book begins with a theoretical description of charge transport in organic semiconductors at the molecular level. It then discusses the current understanding of charge transport in single-crystal devices, small molecules and oligomers, conjugated polymer devices, and charge injection issues in organic transistors. After describing the design rationales and synthetic methodologies used for organic semiconductors and dielectric materials, the book provides an overview of a variety of characterization techniques used to probe interfacial ordering, microstructure, molecular packing, and orientation crucial to device performance. It also describes the different processing techniques for molecules deposited by vacuum and solution, followed by current technological examples that employ OTFTs in their operation. Featuring respected contributors from around the world, this thorough, up-to-date volume presents both the theory behind OFETs and the latest applications of this promising technology.

This work takes advantage of high-resolution silicon stencil masks to build air-stable complementary OTFTs using a low-temperature fabrication process. Plastic electronics based on organic thin-film transistors (OTFTs) pave the way for cheap, flexible and large-area products. Over the past few years, OTFTs have undergone remarkable advances in terms of reliability, performance and scale of integration. Many factors contribute to the allure of this technology; the masks exhibit excellent stiffness and stability, thus allowing OTFTs with submicrometer channel lengths and superb device uniformity to be patterned. Furthermore, the OTFTs employ an ultra-thin gate dielectric that provides a sufficiently high capacitance to enable the transistors to operate at voltages as low as 3 V. The critical challenges in this development are the subtle mechanisms that govern the properties of aggressively scaled OTFTs. These mechanisms, dictated by device physics, are well described and implemented into circuit-design tools to ensure adequate simulation accuracy.

Like its predecessor this book is devoted to the materials, manufacturing and applications aspects of organic thin-film transistors. Once again authored by the most renowned experts from this fascinating and fast-moving area of research, it offers a joint perspective both broad and in-depth on the latest developments in the areas of materials chemistry, transport physics, materials characterization, manufacturing technology, and circuit integration of organic transistors. With its many figures and detailed index, this book once again also serves as a ready reference.

This is a single-source treatment of developments in TFT production from international specialists. It interweaves overlapping areas in multiple disciplines pertinent to transistor fabrication and explores the killer application of amorphous silicon transistors in active matrix liquid crystal displays. It evaluates the preparation of polycrystallin