More than 50% of the total energy produced is typically rejected in the form of waste heat from various processes. The grand challenge is that most of this waste heat is released at temperatures much lower than 1000 C, which makes it difficult to recover it using traditional methods which require higher operating temperatures for thermal energy conversion. In addition, these traditional methods involve different intermediate processes and do not offer direct conversion into electricity. In this regard, thermal energy conversion through thermionic emission can offer direct conversion of waste heat into electricity with highest theoretical efficiency. So, waste heat recovery through thermionic emission energy conversion is of great interest and is the motivation for the present work. However the greatest challenge involves the discovery or availability of the material with appropriate work functions and stability criteria. To address the need for developing suitable materials toward thermionic energy conversion, we investigated phosphorus doping in individual diamond nanocrystals, conical carbon nanostructures (CCNTs) and diamond nanocrystals supported on conical carbon nanostructures. Hybrid architectures, diamond nanocrystals supported on high aspect ratio structures will allow the study of true performance of nanocrystals free from grain boundaries and also offer field enhancements. First, the synthesis of CCNTs over large area and flat substrates is investigated. From the experimental results, we successfully synthesized CCNTs on planar graphite and tungsten foil substrates with areas as large as (>0.5 cm2). A detailed underlying nucleation and growth mechanism was also demonstrated supported with regrowth experiments and kinetic growth model. Secondly, selective nucleation of the diamond crystals on the tips or complete coating on CCNTs was demonstrated and a likely mechanism for the nucleation and growth of diamond crystals is also presented. Thirdly, the field and thermionic emission characteristics from the as synthesized CCNTs have shown to exhibit enhanced emission characteristics such as low turn-on voltages, large field enhancement factor and lower work function values owing to their higher aspect ratios and optimum density overcoming field screening effects. Finally, phosphorus doping into these individual diamond crystals and diamond films was performed and thermionic emission characteristics were studied. Work function values as low as 1.8 eV from diamond films and 2.2 eV from diamond crystals was obtained. In summary, the main outcomes of this work include growth of large area CCNTs on flat substrates, discovery of the enhanced field and thermionic emission characteristics of CCNTs, selective nucleation and phosphorus doping of individual diamond nanocrystals on CCNTs free from grain boundaries and work function value as low as 2.2 eV from thermionic emission from these crystals.

Representing the first text to cover this exciting new area of research, this book will describe synthesis techniques of CNWs, their characterization and various expected applications using CNWs. Carbon-nanowalls (CNWs) can be described as two-dimensional graphite nanostructures with edges comprised of stacks of plane graphene sheets standing almost vertically on the substrate. These sheets form a wall structure with a high aspect ratio. The thickness of CNWs ranges from a few nm to a few tens of nm. The large surface area and sharp edges of CNWs may prove useful for a number of applications such as electrochemical devices, field electron emitters, storage materials for hydrogen gas, catalyst support. In particular, vertically standing CNWs with a high surface-to-volume ratio, serve as an ideal material for catalyst support for fuel cells and in gas storage materials.

This book introduces an innovative and high-efficiency technology for mechanical energy harvesting. The book covers the history and development of triboelectric nanogenerators, basic structures, working principles, performance characterization, and potential applications. It is divided into three parts: Part A illustrates the fundamental working modes of triboelectric nanogenerators with their prototype structures and theoretical analysis; Part B and Part C introduce two categories of applications, namely self-powered systems and self-powered active sensors. The book will be an ideal guide to scientists and engineers beginning to study triboelectric nanogenerators or wishing to deepen their knowledge of the field. Readers will be able to place the technical details about this technology in context, and acquire the necessary skills to reproduce the experimental setups for fabrication and measurement.

This book focuses on the fundamental concepts and physical and chemical aspects of pulsed laser ablation of solid targets in liquid environments and its applications in the preparation of nanomaterials and fabrication of nanostructures. The areas of focus include basic thermodynamic and kinetic processes of laser ablation in liquids, and its applic

Nanotechnology is a vital new area of research and development addressing the control, modification and fabrication of materials, structures and devices with nanometre precision and the synthesis of such structures into systems of micro- and macroscopic dimensions. Future applications of nanoscale science and technology include motors smaller than the diameter of a human hair and single-celled organisms programmed to fabricate materials with nanometer precision. Miniaturisation has revolutionised the semiconductor industry by making possible inexpensive integrated electronic circuits comprised of devices and wires with sub-micrometer dimensions. These integrated circuits are now ubiquitous, controlling everything from cars to toasters. The next level of miniaturisation, beyond sub-micrometer dimensions into nanoscale dimensions (invisible to the unaided human eye) is a booming area of research and development. This is a very hot area of research with large amounts of venture capital and government funding being invested worldwide, as such Nanoscale Science and Technology has a broad appeal based upon an interdisciplinary approach, covering aspects of physics, chemistry, biology, materials science and electronic engineering. Kelsall et al present a coherent approach to nanoscale sciences, which will be invaluable to graduate level students and researchers and practising engineers and product designers.

This substantially updated and augmented second edition adds over 200 pages of text covering and an array of newer developments in nanoscale thermal transport. In Nano/Microscale Heat Transfer, 2nd edition, Dr. Zhang expands his classroom-proven text to incorporate thermal conductivity spectroscopy, time-domain and frequency-domain thermoreflectance techniques, quantum size effect on specific heat, coherent phonon, minimum thermal conductivity, interface thermal conductance, thermal interface materials, 2D sheet materials and their unique thermal properties, soft materials, first-principles simulation, hyperbolic metamaterials, magnetic polaritons, and new near-field radiation experiments and numerical simulations. Informed by over 12 years use, the author’s research experience, and feedback from teaching faculty, the book has been reorganized in many sections and enriched with more examples and homework problems. Solutions for selected problems are also available to qualified faculty via a password-protected website.• Substantially updates and augments the widely adopted original edition, adding over 200 pages and many new illustrations;• Incorporates student and faculty feedback from a decade of classroom use;• Elucidates concepts explained with many examples and illustrations;• Supports student application of theory with 300 homework problems;• Maximizes reader understanding of micro/nanoscale thermophysical properties and processes and how to apply them to thermal science and engineering;• Features MATLAB codes for working with size and temperature effects on thermal conductivity, specific heat of nanostructures, thin-film optics, RCWA, and near-field radiation.

This is a graduate level textbook in nanoscale heat transfer and energy conversion that can also be used as a reference for researchers in the developing field of nanoengineering. It provides a comprehensive overview of microscale heat transfer, focusing on thermal energy storage and transport. Chen broadens the readership by incorporating results from related disciplines, from the point of view of thermal energy storage and transport, and presents related topics on the transport of electrons, phonons, photons, and molecules. This book is part of the MIT-Pappalardo Series in Mechanical Engineering.

Power Electronics Device Applications of Diamond Semiconductors presents state-of-the-art research on diamond growth, doping, device processing, theoretical modeling and device performance. The book begins with a comprehensive and close examination of diamond crystal growth from the vapor phase for epitaxial diamond and wafer preparation. It looks at single crystal vapor deposition (CVD) growth sectors and defect control, ultra high purity SC-CVD, SC diamond wafer CVD, heteroepitaxy on Ir/MqO and needle-induced large area growth, also discussing the latest doping and semiconductor characterization methods, fundamental material properties and device physics. The book concludes with a discussion of circuits and applications, featuring the switching behavior of diamond devices and applications, high frequency and high temperature operation, and potential applications of diamond semiconductors for high voltage devices. - Includes contributions from today's most respected researchers who present the latest results for diamond growth, doping, device fabrication, theoretical modeling and device performance - Examines why diamond semiconductors could lead to superior power electronics - Discusses the main challenges to device realization and the best opportunities for the next generation of power electronics

This book is meant to serve as a textbook for beginners in the field of nanoscience and nanotechnology. It can also be used as additional reading in this multifaceted area. It covers the entire spectrum of nanoscience and technology: introduction, terminology, historical perspectives of this domain of science, unique and widely differing properties, advances in the various synthesis, consolidation and characterization techniques, applications of nanoscience and technology and emerging materials and technologies.