Download or read book Initial stages of organic semiconductor thin film growth written by Primož Rebernik Ribič and published by . This book was released on 2009 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigating the Nucleation Growth and Energy Levels of Organic Semiconductors for High Performance Plastic Electronics written by Ajay Virkar and published by Springer Science & Business Media. This book was released on 2011-09-29 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis details the significant progress made in improving the performance of organic transistors and the network conductivity of carbon nanotubes. The first section investigates organic semiconductor nucleation and growth on the most common dielectric surface used to fabricate organic thin film transistors. The nucleation and growth of the semiconductor was determined to be a critical factor affecting the device performance. Excellent dielectric modification layers, which promote desirable semiconductor growth leading to high conductivity were identified, and a technologically relevant deposition technique was developed to fabricate high quality dielectric modification layers over large areas. This may represent an important step towards the realization of large area organic circuity. In the final section, lessons learned from studying organic semiconductor nucleation and growth were utilized to improve the conductivity of carbon nanotube networks. Selective nucleation of materials at the junctions between nanotubes in the network significantly decreased the network's sheet resistance. The resulting networks may be promising candidates for transparent electrodes with a variety of optoelectronic applications.

Download or read book The Initial Stages of Atomic Layer Deposition on Substrates Modified by Organic Thin Films written by Kevin James Hughes and published by . This book was released on 2011 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic layer deposition (ALD) provides the ability to deposit highly conformal thin films with essentially molecular level control over film thickness. These characteristics have made it an active area of research for a number of applications, notably in the field of semiconductor devices. The focus of the work presented here is on the initial stages of film growth, including the first interaction of gas phase ALD precursors with the substrate, and the period in which the growing surface transitions from the starting substrate to the steady-state growing film. Of particular interest are substrates modified using thin organic films. These organic films are used to alter the identity, density and spatial extent of functional groups on the surface. We begin with a review of the prior work in this area, focusing on the ALD of TiNx on a variety of organic films, including self-assembled monolayers with various endgroup chemistries, and branched films with a more 3-d distribution of functional groups. Here connections are observed between the initial interactions of the gas phase precursors with the organic film, and the subsequent stages of ALD growth. A relationship between the initial rate of ALD growth and the resulting film morphology is also observed, and can be explained by a variation in nucleation site density due to the structure of the organic film. The next section involves the ALD of a range of materials (Al2O3, HfO2, Ta2O5, and TaNx), on a single organic layer, branched poly(ethylene imine) (PEI). Here, the presence of the organic layer causes an attenuation in the amount of material deposited per ALD cycle in the initial stages of growth. A strong correlation was found between the thermodynamic driving force of the ALD reaction and the degree of attenuation, suggesting that ALD processes in which there is a strong driving force (or low activation energy) for the formation of the final products can more easily overcome the obstacles presented by the organic layer. The ALD of one material, TaNx, was examined in more detail using in situ XPS. Substrates in this study included nonporous SiO2, a porous low dielectric constant or 'low-[kappa]' material, and both substrates modified by PEI films. PEI was used here in part because of the tendency of smaller molecules to infiltrate and deposit within the pore network of the low-[kappa]. The chemical structure of the chemisorbed tantalum precursor, Ta[N(CH3)2]5, after the first cycle of ALD, as well as the oxidation state and chemical composition of the TaNx film in the first 10 cycles (~ 610 Å) were strongly affected by the starting substrate. Substrates with a high density of oxygen containing groups led to a more oxidized TaNx film, and less efficient incorporation of N in a nitride binding state. Furthermore, the presence of a PEI film enhanced the growth of TaNx at the surface of the porous low-[kappa], and limited infiltration of the pore network by the gas phase ALD precursors. A final set of experiments involved the early stages of cobalt film formation on tantalum substrates using chemical vapor deposition with the metalorganic precursor dicobalt hexacarbonyl tert-butylacetylene (CCTBA). Here it was found that growth proceeded in two phases. The first involved the formation of an intermixed cobalt/tantalum layer, while the second took place after the intermixed layer was covered and was characterized by the formation of a mixed carbon/cobalt film.

Download or read book Interface Controlled Organic Thin Films written by Horst-Günter Rubahn and published by Springer Science & Business Media. This book was released on 2009-06-12 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic semiconductors are a central topic of advanced materials research. The book is aiming at bridging the gap between the development and production of devices and basic research on thin film characterisation using cutting-edge techniques in surface and interface science. Topics involve organic molecular-based sensors; interfaces in organic diodes and transistors; mobility in organic field effect transistors and space charge problems; integration of optoelectronic nanostructures; nonlinear optical properties of organic nanostructures; the wetting layer problem; how to get from functionalized molecules to nanoaggregates; optical, electrical and mechanical properties of organic nanofibers as well; as near field investigations of organic thin films.

Download or read book Introduction to Organic Semiconductor Heterojunctions written by Donghang Yan and published by John Wiley & Sons. This book was released on 2010-09-16 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is well known that most important electronic devices use Schottky junctions and heterojunctions. Unfortunately there is not an advanced book introducing heterojunctions systematically. Introduction to Organic Semiconductor Heterojunctions fills the gap. In this book, the authors provide a comprehensive discussion and systematic introduction on the state-of-the-art technologies as well as application of organic semiconductor heterojunctions. First book to systematically introduce organic heterojunctions Arms readers with theoretical, experimental and applied aspects of organic heterojunctions The Chinese edition of the book is part of the Chinese Academy of Sciences’ Distinguished Young Scholar Scientific Book Series Introduction to Organic Semiconductor Heterojunctions is an ideal and valued reference for researchers and graduate students focusing on organic thin film devices like organic light-emitting diodes (OLEDs), organic photovoltaic (OPV) cells, and organic field-effect transistors (OFETs). Instructors can use the book as a supplementary text for a semiconductor physics or organic electronics course, giving students a better feel for the application of organic thin film devices.

Download or read book Structure and Transport in Organic Semiconductor Thin Films written by Sandra Elizabeth Fritz Vos and published by . This book was released on 2006 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Real time Studies of Thin Film Growth of Organic Semiconductors written by Stefan M. Kowarik and published by . This book was released on 2006 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Crystal Growth written by Tom Kuech and published by Elsevier. This book was released on 2014-11-02 with total page 1384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume IIIA Basic TechniquesHandbook of Crystal Growth, Second Edition Volume IIIA (Basic Techniques), edited by chemical and biological engineering expert Thomas F. Kuech, presents the underpinning science and technology associated with epitaxial growth as well as highlighting many of the chief and burgeoning areas for epitaxial growth. Volume IIIA focuses on major growth techniques which are used both in the scientific investigation of crystal growth processes and commercial development of advanced epitaxial structures. Techniques based on vacuum deposition, vapor phase epitaxy, and liquid and solid phase epitaxy are presented along with new techniques for the development of three-dimensional nano-and micro-structures.Volume IIIB Materials, Processes, and TechnologyHandbook of Crystal Growth, Second Edition Volume IIIB (Materials, Processes, and Technology), edited by chemical and biological engineering expert Thomas F. Kuech, describes both specific techniques for epitaxial growth as well as an array of materials-specific growth processes. The volume begins by presenting variations on epitaxial growth process where the kinetic processes are used to develop new types of materials at low temperatures. Optical and physical characterizations of epitaxial films are discussed for both in situ and exit to characterization of epitaxial materials. The remainder of the volume presents both the epitaxial growth processes associated with key technology materials as well as unique structures such as monolayer and two dimensional materials.Volume IIIA Basic Techniques - Provides an introduction to the chief epitaxial growth processes and the underpinning scientific concepts used to understand and develop new processes. - Presents new techniques and technologies for the development of three-dimensional structures such as quantum dots, nano-wires, rods and patterned growth - Introduces and utilizes basic concepts of thermodynamics, transport, and a wide cross-section of kinetic processes which form the atomic level text of growth process Volume IIIB Materials, Processes, and Technology - Describes atomic level epitaxial deposition and other low temperature growth techniques - Presents both the development of thermal and lattice mismatched streams as the techniques used to characterize the structural properties of these materials - Presents in-depth discussion of the epitaxial growth techniques associated with silicone silicone-based materials, compound semiconductors, semiconducting nitrides, and refractory materials

Download or read book Thin Film Growth Techniques for Low Dimensional Structures written by R.F.C. Farrow and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work represents the account of a NATO Advanced Research Workshop on "Thin Film Growth Techniques for Low Dimensional Structures", held at the University of Sussex, Brighton, England from 15-19 Sept. 1986. The objective of the workshop was to review the problems of the growth and characterisation of thin semiconductor and metal layers. Recent advances in deposition techniques have made it possible to design new material which is based on ultra-thin layers and this is now posing challenges for scientists, technologists and engineers in the assessment and utilisation of such new material. Molecular beam epitaxy (MBE) has become well established as a method for growing thin single crystal layers of semiconductors. Until recently, MBE was confined to the growth of III-V compounds and alloys, but now it is being used for group IV semiconductors and II-VI compounds. Examples of such work are given in this volume. MBE has one major advantage over other crystal growth techniques in that the structure of the growing layer can be continuously monitored using reflection high energy electron diffraction (RHEED). This technique has offered a rare bonus in that the time dependent intensity variations of RHEED can be used to determine growth rates and alloy composition rather precisely. Indeed, a great deal of new information about the kinetics of crystal growth from the vapour phase is beginning to emerge.

Download or read book Optoelectronics written by Sergei Pyshkin and published by BoD – Books on Demand. This book was released on 2013-01-16 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optoelectronics - Advanced Materials and Devices is a second edition following the initial Optoelectronics - Materials and Techniques book published in 2011 as part of the InTech collection of international works on optoelectronics. Optoelectronics, as the discipline devoted to the study and application of electronic devices that emit, detect, and otherwise control light, has widely proliferated globally and enabled many of today's modern conveniences. Because of this ubiquity, new applications and novel optical phenomena continue to drive innovation. Accordingly, as with the first book of the collection, this book covers recent achievements by specialists around the world. The growing number of countries participating in this endeavor including now Brazil, Canada, China, Egypt, France, Germany, India, Italy, Japan, Malaysia, Mexico, Moldova, Morocco, Netherlands, Portugal, Romania, Saudi Arabia, South Korea, Taiwan, Ukraine, USA, and Vietnam as well as joint participation of the US and Moldova scientists in edition of this book and writing one of its Chapters testify to the unifying effect of science. An interested reader will find in the book the description of properties and applications employing organic and inorganic materials, such as different polymers, oxides and semiconductors, as well as the methods of fabrication and analysis of operation and regions of application of modern optoelectronic devices.

Download or read book Organic Thin Film Transistors with Mono crystalline Rubrene Films by Horizontal Hot Wall Deposition written by Yi Chen and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Organic Thin Films and Surfaces Directions for The Nineties written by Abraham Ulman and published by Elsevier. This book was released on 2013-10-22 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics of Thin Films has been one of the longest running continuing series in thin film science consisting of 20 volumes since 1963. The series contains some of the highest quality studies of the properties ofvarious thin films materials and systems.In order to be able to reflect the development of todays science and to cover all modern aspects of thin films, the series, beginning with Volume 20, will move beyond the basic physics of thin films. It will address the most important aspects of both inorganic and organic thin films, in both their theoretical as well as technological aspects. Therefore, in order to reflect the modern technology-oriented problems, the title has been slightly modified from Physics of Thin Films to Thin Films.Edited by Abraham Ulman, Organic Thin Films and Surfaces: Directions for the Nineties will be the first volume to link two dynamic areas in the physical sciences--organic thin films and surface science. Contributions from leading experts in the field cover a range of important topics on the processing, characterization, and applications of organic thin films.

Download or read book Organic Field Effect Transistors written by Zhenan Bao and published by CRC Press. This book was released on 2018-10-03 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A Theoretical and Experimental Study Into the Kinetics of Solution Phase Thin Film Deposition written by Cyrus Schaaf and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of electronic and optoelectronic devices based on solution-processed organic semiconductor layers is strongly influenced by their mesoscale polycrystalline structure, including domain size and spatial distributions. In solution-processed films prepared by spin casting, solvent-based printing, and related methods, morphology is governed by a combination of interrelated thermodynamic and kinetic factors. Classical models of crystal formation in bulk solution or on bare surfaces in vacuum-deposited films fail to adequately capture these effects; the current theoretical understanding of crystallization in solution-deposited films is generally unable to provide much insight, let alone predictive design guidance for tailoring films with specific structural characteristics for a given set of experimental conditions and chemical properties. In this thesis solution-phase thin film formation has been studied for the purpose of developing and new experimental techniques new models for understanding and predicting mesoscale film structure and crystal morphology. I will describe how nucleation can be modeled, and the predictions tested against experiment, by an approach that enables quantitative prediction of crystal coverage and intercrystalline spacing statistics as a function of processing conditions, using only a small number of experimentally-measureable parameters. To do this, a model is introduced that combines a mean-field rate equation treatment of monomer aggregation kinetics with classical nucleation theory and a supersaturation-dependent critical nucleus size to solve for the quasi-two-dimensional temporally- and spatially-varying monomer concentration and nucleation rate. Excellent agreement is observed with measured nucleation densities and inter-domain radial distribution functions in submonolayer tetracene films. The model leads to the first universal set of predictive design rules for solution-phase thin film growth capable of guiding the selection of experimental conditions for truly engineered morphological control. Accompanying this theoretical work a first of its kind experiment is also reported, in which monomer concentration has been spatially and temporally mapped in real time during the film formation process. Through the use of high resolution dark field fluorescence microscopy employing an internal fluorescent standard and multi-wavelength imaging optics the concentration dependence is visualized throughout all regimes of thin film formation. In situ measurements of local concentration contributes to the development of models which treat the role of variations in monomer concentration on mesoscale film morphology of polycrystalline thin films. This work opens the door to numerous studies enabling further development of models which allow for predictive control of polycrystalline thin films in solution-phase deposition techniques. In addition to nucleation, growth of crystalline films is modeled through a set of numerical and computational methods which provide insight into the main factors influencing crystal growth habit. It is shown that crystal capture rate correlation with physical properties displays a distinct lack of agreement between the spacing and initial sizes of crystals with their relative growth rates. This lack of correlation points to the need for more sophisticated models. Through the use of a mean field numerical calculation of the volumetric growth rate changes in crystal morphology can be attributed to a variable sticking probability which depends on the crystal face. Kinetic Monte Carlo simulations are used to directly probe the physics which explain the deviation from the typical single sticking coefficient capture model. The change in shape at long deposition times further suggests that crystal growth occurs in distinct regimes which dictate the final morphology of the crystals. This work provides an explanation to the change in shape of crystalline material at long deposition times which can be used to develop models to predict final crystal morphology. This thesis is comprised of several parts. In the first chapter the broader context of the work is discussed. In chapter 2, I discuss the scientific background laying the foundation for theoretical models into solution-phase deposition. In the third chapter, I describe the experimental system as well as results from various measurements of fundamental chemical and physical properties needed later. The fourth chapter describes a set of models which I have developed to predict mesoscale film structure to create a set of universal design rules in order to engineer thin films grown in the solution-phase. In chapter 5, I describe a state of the art experimental set up allowing for monomer concentration to be mapped in real time. Finally in the last chapter I describe a set of exploratory models to describe change in crystal morphology during the course of thin film formation. This thesis creates new understanding, which will allow for an increase in production of thin films for applications where strict control over domain size, shape, spacing, and crystallographic orientation.

Download or read book Investigating the Nucleation Growth and Energy Levels of Organic Semiconductors for High Performance Plastic Electronics written by Ajay Anil Virkar and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Plastic or organic electronics offer several advantages over conventional inorganic technologies. Firstly, the molecular structure of organic semiconductors and conductors can be tuned for various applications using synthetic chemistry. In addition organic thin films are flexible, and can be processed and patterned inexpensively. However, improving the thin film conductivity of organic semiconductors and conductors is necessary for widespread application and adoption. The overall goal of this thesis is to investigate and control organic small molecule growth at surfaces in order to improve the performance of organic electronic devices. In first part of the thesis, improving the charge carrier mobility of organic thin film transistors (OTFTs), the building block for plastic electronics, is discussed. The nucleation, stability and thin film growth of model organic semiconductors such as pentacene and C60 are described with focus on correlating thin film structure to charge carrier mobility. More specifically, pentacene nucleation and growth on the most common substrate for OTFTs, an octadecylsilane (OTS) monolayer modified silicon oxide surface, is investigated. The role of the density of the OTS was determined to be a critical device parameter that impacts organic semiconductor nucleation and growth, and the charge carrier mobility, as the OTS transitions from an amorphous monolayer into a crystalline one. Dense OTS monolayers were fabricated using the well known ultrathin film Langmuir Blodgett (LB) technique, as well as a new spin-coating technique developed in our lab. The crystalline OTS monolayer serves as an excellent template for promoting desirable organic semiconductor thin film growth leading to high performance transistors. Therefore a crystalline OTS dielectric surface modification layer, which greatly improves organic semiconductor performance, may be important for the future success of OTFTs and organic circuits. In the second part of the thesis, lessons learned from studying organic semiconductor nucleation and growth are applied to improving the conductivity of carbon nanotube (CNT) networks for transparent electrode applications. Selective growth of organic small molecules with low molecular orbital energies was used to greatly reduce the sheet resistance of CNT films by both decreasing junction resistances and stable doping of the semiconducting CNTs. The result is a material which has the highest value (in terms of transparency and sheet conductivity) of any carbon based transparent electrode.

Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Second Generation HTS Conductors written by Amit Goyal and published by Springer Science & Business Media. This book was released on 2006-06-26 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: The third method invented is called the Rolling-assisted-biaxially-textured-substrates (RABiTS). The book is divided into four sections. The first section discusses the three methods to fabricate biaxially textured substrates, upon which, epitaxial YBCO or other HTS materials can be deposited to realize a single-crystal-like HTS wire. The second section includes chapters on various methods of HTS deposition such as pulsed laser ablation (PLD), thermal co-evaporation, sputtering, pulsed electron beam deposition, ex-situ BaF2 by co-evaporation flowed by annealing, chemical solution based ex-situ processes, jet vapor deposition, metal organic chemical vapor deposition (MOCVD), and liquid phase epitaxy (LPE). The third section includes detailed chapters on other HTS materials such as the various Tl-based and Hg-based conductors. These Second-Generation HTS conductors, also referred to as "Coated conductors" represent one of the most exciting developments in HTS technology.