At the Material Research Society Spring 2013 meeting, held in San Francisco April 1-5, 2013, three symposia were held that focused on thermal-to-electric energy conversion and thermal transport: Symposium H: Nanoscale Thermoelectrics-Materials and Transport Phenomena - II, Symposium I: Materials for Solid-State Refrigeration, and Symposium V: Nanoscale Heat Transport-From Fundamentals to Devices. Although each technical session was focused on a different aspect of this subject, the intellectual commensurability of these symposia warranted the publication of their proceedings in a single volume.

At the Material Research Society Spring 2013 meeting, held in San Francisco April 1-5, 2013, three symposia were held that focused on thermal-to-electric energy conversion and thermal transport: Symposium H: Nanoscale Thermoelectrics-Materials and Transport Phenomena - II, Symposium I: Materials for Solid-State Refrigeration, and Symposium V: Nanoscale Heat Transport-From Fundamentals to Devices. Although each technical session was focused on a different aspect of this subject, the intellectual commensurability of these symposia warranted the publication of their proceedings in a single volume.

Environmental and economic concerns have significantly spurred the search for novel, high-performance thermoelectric materials for energy conversion in small-scale power generation and refrigeration devices. This quest has been mainly fueled by the introduction of new designs and the synthesis of new materials. In fact, good thermoelectric material

Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The Willardson and Beer series, as it is widely known, has succeeded in producing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition will be maintained and even expanded.Thermoelectric materials may be used for solid state refrigeration or power generation applications via the large Peltier effect in these materials. To be an effective thermoelectric material, a material must possess a large Seebeck coefficient, a low resistivity and a low thermal conductivity. Due to increased need for alternative energy sources providing environmentally friendly refrigeration and power generation, thermoelectric materials research experienced a rebirth in the mid 1990's. Semiconductors and Semimetals, Volume 70: Recent Trends in Thermoelectric Materials Research: Part Two provides an overview of much of this research in thermoelectric materials during the decade of the 1990's. New materials and new material concepts such as quantum well and superlattice structures gave hope to the possibilities that might be achieved. An effort was made to focus on these new materials and not on materials such as BiTe alloys, since such recent reviews are available. Experts in the field who were active researchers during this period were the primary authors to this series of review articles. This is the most complete collection of review articles that are primarily focussed on new materials and new concepts that is existence to date.

Thermoelectric materials are utilized in a wide variety of applications related to solid-state refrigeration or small-scale power generation. More specifically, these applications range from beverage coolers to power generation for deep-space probes such as the Voyager missions. Over the past several years, however, research in the field of thermoelectric materials has been undergoing a rapid rebirth. The enhanced interest in better thermoelectric materials has been driven by the need for much higher performance and new temperature regimes in thermoelectric devices. The focus of this volume is embodied in the title, New Directions and Approaches. The volume emphasizes the multidisciplinary nature of the research needed to advance the science and technology. Theoretical studies in materials design, which provide guidance to the experimentalist, are reviewed. Experimental efforts are also featured and include new capabilities in solid-state synthesis, thin-film and superlattice development, and new developments in property measurement of which thermal conductivity will play a central role. New ideas in device design are also discussed.

Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The Willardson and Beer series, as it is widely known, has succeeded in producing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition will be maintained and even expanded. Thermoelectric materials may be used for solid state refrigeration or power generation applications via the large Peltier effect in these materials. To be an effective thermoelectric material, a material must possess a large Seebeck coefficient, a low resistivity and a low thermal conductivity. Due to increased need for alternative energy sources providing environmentally friendly refrigeration and power generation, thermoelectric materials research experienced a rebirth in the mid 1990's. Semiconductors and Semimetals, Volume 71: Recent Trends in Thermoelectric Materials Research: Part Three provides an overview of much of this research in thermoelectric materials during the decade of the 1990's. New materials and new material concepts such as quantum well and superlattice structures gave hope to the possibilities that might be achieved. An effort was made to focus on these new materials and not on materials such as BiTe alloys, since such recent reviews are available. Experts in the field who were active researchers during this period were the primary authors to this series of review articles. This is the most complete collection of review articles that are primarily focussed on new materials and new concepts that is existence to date.

A brief review of various techniques to engineer nanoscale thermal and electrical properties of materials is given. The main emphasis is on various energy conversion mechanisms, particularly, thermo electric refrigeration and power generation. Recent experimental and theoretical results on superlattice and quantum dot thermoelectrics and solidstate and vacuum thermionic thin film devices are reviewed. We also present an overview of the research activities at the multi university Thermionic Energy Conversion Center on the design of solid-state and vacuum devices that could convert heat into electricity with hot side temperatures ranging from 300 to 650C and with high conversion efficiency.