Unique carbon-nano-structure for high quality electron-emitter to be employed in a variety of applications

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Autor principal: Akio Hiraki
Formato: Artículo científico
Lenguaje:en
Publicado: Sociedad Mexicana de Física A.C. 2008
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author Akio Hiraki
author_facet Akio Hiraki
contents Unique carbon-nano-structure for high quality electron-emitter to be employed in a variety of applications Akio Hiraki Hirohisa Hirak Física, Astronomía y Matemáticas carbon CVD diamond nanostructure Electron emitters carbon nano wires There have been many trials to employ nano-carbon materials, such as carbon-nano-tubes and nano-diamond films, as electron-emitter. Several reasons exist why the nano-carbon materials are good for the emitter. They are, in addition to (a) unique morphological shapes of the materials good for the emitter- the high aspect ratio of the carbon-nano-tube is a good example-, (b) sturdiness(they can even be formed in a plasma), (c) high thermal conductivity (current density in the electron-emitting nano-structure is high, thus it is vital to provide effective Joule-heat dissipation), and (d) easiness of the fabrication of the electron-emitting carbon materials. In order to fabricate good electron emitters, we have long been trying to employ a variety of fabrication CVD methods and fabricating conditions (starting CVD gas, pressure, temperature, substrate materials and so on).Then recently our emitters have shown a world-top-ranking property: very low turnon- voltage(0.5V/¹m induce 10¹A/cm2 of emission current) and high current at low applied voltage with gap distance of 1mm(1mA/cm2 at 1.1V/¹m and 100/ at 2V/¹m). This excellent property comes from a carbon-nano-structure which we call CNX(Carbon-Nano-eXit). In addition, these emitter can be formed on a variety of substrates(Ni, Ni-Cr, SUS or others), in forms of wire or pipe, very quickly. Namely, by one reactor, it is possible to fabricate 50>100 km of "wire or pipe type emitter" per month.The wire type emitter is good for both high field concentration and avoiding the so-called "edge-effect".Then using these emitters, we are able to fabricate Mercury-free fluorescence lamps with high efficiency (>60lm/watt) and high brightness of more than 105cd/m2(white-light). 2008 artículo científico 0035-001X https://www.redalyc.org/articulo.oa?id=57019061007 en http://www.redalyc.org/revista.oa?id=570 Revista Mexicana de Física application/pdf Sociedad Mexicana de Física A.C. Revista Mexicana de Física (México) Num.2 Vol.54
format Artículo científico
id redalyc_57019061007
institution Redalyc
language en
publishDate 2008
publisher Sociedad Mexicana de Física A.C.
spellingShingle Unique carbon-nano-structure for high quality electron-emitter to be employed in a variety of applications
Akio Hiraki
Física, Astronomía y Matemáticas
carbon
CVD diamond
nanostructure
Electron emitters
carbon nano wires
Unique carbon-nano-structure for high quality electron-emitter to be employed in a variety of applications Akio Hiraki Hirohisa Hirak Física, Astronomía y Matemáticas carbon CVD diamond nanostructure Electron emitters carbon nano wires There have been many trials to employ nano-carbon materials, such as carbon-nano-tubes and nano-diamond films, as electron-emitter. Several reasons exist why the nano-carbon materials are good for the emitter. They are, in addition to (a) unique morphological shapes of the materials good for the emitter- the high aspect ratio of the carbon-nano-tube is a good example-, (b) sturdiness(they can even be formed in a plasma), (c) high thermal conductivity (current density in the electron-emitting nano-structure is high, thus it is vital to provide effective Joule-heat dissipation), and (d) easiness of the fabrication of the electron-emitting carbon materials. In order to fabricate good electron emitters, we have long been trying to employ a variety of fabrication CVD methods and fabricating conditions (starting CVD gas, pressure, temperature, substrate materials and so on).Then recently our emitters have shown a world-top-ranking property: very low turnon- voltage(0.5V/¹m induce 10¹A/cm2 of emission current) and high current at low applied voltage with gap distance of 1mm(1mA/cm2 at 1.1V/¹m and 100/ at 2V/¹m). This excellent property comes from a carbon-nano-structure which we call CNX(Carbon-Nano-eXit). In addition, these emitter can be formed on a variety of substrates(Ni, Ni-Cr, SUS or others), in forms of wire or pipe, very quickly. Namely, by one reactor, it is possible to fabricate 50>100 km of "wire or pipe type emitter" per month.The wire type emitter is good for both high field concentration and avoiding the so-called "edge-effect".Then using these emitters, we are able to fabricate Mercury-free fluorescence lamps with high efficiency (>60lm/watt) and high brightness of more than 105cd/m2(white-light). 2008 artículo científico 0035-001X https://www.redalyc.org/articulo.oa?id=57019061007 en http://www.redalyc.org/revista.oa?id=570 Revista Mexicana de Física application/pdf Sociedad Mexicana de Física A.C. Revista Mexicana de Física (México) Num.2 Vol.54
title Unique carbon-nano-structure for high quality electron-emitter to be employed in a variety of applications
topic Física, Astronomía y Matemáticas
carbon
CVD diamond
nanostructure
Electron emitters
carbon nano wires
url https://www.redalyc.org/articulo.oa?id=57019061007