Nanostructured Carbon Electron Emitters and Its Applications

Carbon forms a variety of allotropes due to the diverse hybridization of s- and p-electron orbitals, including the time-honored graphite and diamond as well as new forms such as C60 fullerene, nanotubes, graphene, and carbyne. The new family of carbon isotopes--fullerene, nanotubes, graphene, and carbyne--is called ＂nanostructured carbon＂ or ＂nanocarbon.＂ These isotopes exhibit extreme properties such as ultrahigh mechanical strength, ultrahigh charge-carrier mobility, and high thermal conductivity, attracting considerable attention for their electronic and mechanical applications as well as for exploring new physics and chemistry in the field of basic materials science. Electron sources are important in a wide range of areas, from basic physics and scientific instruments to medical and industrial applications. Carbon nanotubes (CNTs) and graphene behave as excellent electron-field emitters owing to their exceptional properties and offer several benefits compared to traditional cathodes. Field emission (FE) produces very intense electron currents from a small surface area with a narrow energy spread, providing a highly coherent electron beam--a combination that not only provides us with the brightest electron sources but also explores a new field of electron beam-related research.

This book presents the enthusiastic research and development of CNT-based FE devices and focuses on the fundamental aspects of FE from nanocarbon materials, including CNTs and graphene, and the latest research findings related to it. It discusses applications of FE to X-ray and UV generation and reviews electron sources in vacuum electronic devices and space thrusters. Finally, it reports on the new forms of carbon produced via FE from CNT.

Yahachi Saito received his doctorate in Engineering from Nagoya University in 1980 and had held professorial positions at Toyohashi University of Technology (1981-1985) and Mie University (1990-2004) in addition to Nagoya University (1985-1990, 2004-2018). He had also spent time as a visiting scientist at AT&T Bell Laboratories. He is now a fellow at Toyota Physical & Chemical Research Institute.

Saito’s area of expertise encompasses the synthesis, characterization and application of nanometer scale materials, especially inorganic atomic clusters and fine particles, fullerenes, carbon nanotubes (CNTs) and graphene. He has studied CNT field emitters since 1996, collaborating with Noritake Itron Corp since 1997 for the development of display devices using CNTs as a cold cathode. They demonstrated the world’s first CNT-based display device at the SID International Conference in 1998. Saito is the recipient of a number of awards, including the Yazaki Arts and Science Award (2004), the Prize for Science and Technology of the Ministry of Education, Culture, Sports Science and Technology (2006), the 2007 SID Int. Symp. Distinguished Paper Award, and Fellow of Japan Society of Applied Physics (2008). 278 publications in peer-reviewed journals and 5 books.