Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This thesis considers molecular orientation in thin films and introduces an optical model describing this orientation as applied to organic light-emitting diodes (OLEDs). It also describes the electronic structure of intermolecular charge transfer excitons correlated to molecular orientation in solids. It has long been known that molecular orientation influences the electrical and optical properties of molecular films. One notable example is in liquid crystals where rigid rod or disk shaped molecules are commonly used. Understanding the origin of the molecular orientation and its control by surface treatment and electric field resulted in the development of liquid crystal displays. The same thing has happened in organic electronics, and considerable effort has been devoted to understanding and controlling molecular orientation in solid films to improve charge carrier mobility and light absorption, ultimately to improve the performance of organic solar cells and thin film transistors. In contrast, less attention has been paid to molecular orientation and its influence on the characteristics of OLEDs, probably because of the use of amorphous films rather than micro-crystalline films, and it is only in recent years that some molecular films are known to have preferred orientation. This thesis addresses this topic, focusing on OLEDs, describing the origin and control of the orientation of phosphorescent Ir complexes possessing spherical shape rather than rod or disk shape, the simulation of the optical characteristics of OLEDs influenced by preferred molecular orientation, and finally the orientation of intermolecular charge transfer excitons and its correlation to electronic structures in thin films.

Surfaces (Physics). --- Electronics. --- Optical materials. --- Surface and Interface Science, Thin Films. --- Surfaces and Interfaces, Thin Films. --- Electronics and Microelectronics, Instrumentation. --- Optical and Electronic Materials. --- Classical Electrodynamics. --- Surfaces (Physics) --- Physics --- Surface chemistry --- Surfaces (Technology) --- Optics --- Materials --- Electrical engineering --- Physical sciences

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This book highlights the origin of low external quantum efficiency for deep ultraviolet light-emitting diodes (DUV LEDs). In addition, it puts forward solutions for increasing the internal quantum efficiency and the light extraction efficiency of DUV LEDs. The book chiefly concentrates on approaches that can be used to improve the crystalline quality, increase carrier injection, reduce the polarization-induced electric field within multiple quantum wells, suppress the TM polarization emission, and enhance the light escape from the semiconductor layer. It also demonstrates insightful device physics for DUV LEDs, which will greatly benefit the optoelectronic community.

Optical materials. --- Microwaves. --- Optical and Electronic Materials. --- Microwaves, RF and Optical Engineering. --- Optics, Lasers, Photonics, Optical Devices. --- Signal, Image and Speech Processing. --- Hertzian waves --- Electric waves --- Electromagnetic waves --- Geomagnetic micropulsations --- Radio waves --- Shortwave radio --- Optics --- Materials

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This book includes the fundamental science and applications of carbon-based materials, in particular fused polycyclic hydrocarbon, fullerene, diamond, carbides, graphite and graphene etc. During the past decade, these carbon-based materials have attracted much interest from many scientists and engineers because of their exciting physical properties and potential application toward electronic and energy devices. In this book, the fundamental theory referring to these materials, their syntheses and characterizations, the physical properties (physics), and the applications are fully described, which will contribute to an advancement of not only basic science in this research field but also technology using these materials. The book's targets are researchers and engineers in the field and graduate school students who specialize in physics, chemistry, and materials science. Thus, this book addresses the physics and chemistry of the principal materials in the twenty-first century. .

Optical materials. --- Electronic materials. --- Solid state physics. --- Physical chemistry. --- Organic chemistry. --- Optical and Electronic Materials. --- Solid State Physics. --- Physical Chemistry. --- Organic Chemistry. --- Organic chemistry --- Chemistry --- Chemistry, Theoretical --- Physical chemistry --- Theoretical chemistry --- Physics --- Solids --- Electronic materials --- Optics --- Materials

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This book introduces physical effects and fundamentals of piezoelectric sensors and actuators. It gives a comprehensive overview of piezoelectric materials such as quartz crystals and polycrystalline ceramic materials. Different modeling approaches and methods to precisely predict the behavior of piezoelectric devices are described. Furthermore, a simulation-based approach is detailed which enables the reliable characterization of sensor and actuator materials. One focus of the book lies on piezoelectric ultrasonic transducers. An optical approach is presented that allows the quantitative determination of the resulting sound fields. The book also deals with various applications of piezoelectric sensors and actuators. In particular, the studied application areas are · process measurement technology, · ultrasonic imaging, · piezoelectric positioning systems and · piezoelectric motors. The book addresses students, academic as well as industrial reseachers and development engineers who are concerned with piezoelectric sensors and actuators.

Piezoelectric devices. --- Actuators. --- Optical materials. --- Engineering. --- Optical and Electronic Materials. --- Nanotechnology and Microengineering. --- Control and Systems Theory. --- Construction --- Industrial arts --- Technology --- Optics --- Materials --- Electronic materials. --- Nanotechnology. --- Control engineering. --- Electronic materials --- Control engineering --- Control equipment --- Control theory --- Engineering instruments --- Automation --- Programmable controllers --- Molecular technology --- Nanoscale technology --- High technology

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

This book focuses on essential synaptic plasticity emulations and neuromorphic computing applications realized with the aid of three-terminal synaptic devices based on ion-coupled oxide-based electric-double-layer (EDL) transistors. To replicate the robust, plastic and fault-tolerant computational power of the human brain, the emulation of essential synaptic plasticity and computation of neurons/synapse by electronic devices are generally considered to be key steps. The book shows that the formation of an EDL at the dielectric/channel interface that slightly lags behind the stimuli can be attributed to the electrostatic coupling between ions and electrons; this mechanism underlies the emulation of short-term synaptic behaviors. Furthermore, it demonstrates that electrochemical doping/dedoping processes in the semiconducting channel by penetrated ions from electrolyte can be utilized for the emulation of long-term synaptic behaviors. Lastly, it applies these synaptic transistors in an artificial visual system to demonstrate the potential for constructing neuromorphic systems. Accordingly, the book offers a unique resource on understanding the brain-machine interface, brain-like chips, artificial cognitive systems, etc. .

Neuromorphics. --- Transistors. --- Optical materials. --- Biomaterials. --- Neurosciences. --- Optical and Electronic Materials. --- Solid State Physics. --- Electronic Circuits and Devices. --- Neural sciences --- Neurological sciences --- Neuroscience --- Medical sciences --- Nervous system --- Biocompatible materials --- Biomaterials --- Medical materials --- Medicine --- Biomedical engineering --- Materials --- Biocompatibility --- Prosthesis --- Optics --- Electronic materials. --- Solid state physics. --- Electronic circuits. --- Electron-tube circuits --- Electric circuits --- Electron tubes --- Electronics --- Physics --- Solids --- Electronic materials --- Bioartificial materials --- Hemocompatible materials --- Biomaterials (Biomedical materials)