Electron emitter diamond

Apart from transistors, several other solid state devices have been discussed [78], like junctions, photon and electron beam switches and various kinds of sensors. One property of diamond which has stimulated considerable interest in the recent years is the negative electron affinity (NEA) of suitably prepared surfaces [78,80]. The electron affinity, of a material is defined as the difference between the energy of a free electron in vacuum and the bottom of the conduction band Fyac - E. In Fig. 8 the electronic bands of p-doped clean and H-terminated (111) diamond surfaces near the surface are depicted, based on the results of UV-photoemission measurements. For the H-terminated surface, the electron affinity becomes negative once an electron is injected into the conduction band from a suitable contact or by UV excitation, it will easily leave the crystal and be emitted into vacuum. This effect, which is also observed on monohydride terminated (100) surfaces, is not unique to diamond but was also observed in a few other semieonductors with high band gaps [80]. Apart from a scientific interest, the NEA of diamond makes it an attractive eandidate for the replacement of thermionic emitters as electron beam sourees and as a miniature electron emitter for field emission displays. 

Diamond research in these areas continued to advance into the 1990s, less so in the United States and more so in Europe and Japan. During this period, the cost of producing diamond was significantly reduced due to improvements in the nucleation and growth rates. More was learned about the mechanisms and kinetics of diamond synthesis. The use of diamond as an electron emitter became an active area of research due to the negative... 

When techniques for producing smooth, adherant diamond films are developed, it is expected that they will have extensive application in the semiconductor packaging industry because of diamond s high thermal conductivity (about five times that of copper) and high electrical resistivity. Diamond can also be used as a cold cathode electron emitter and, as such, is of interest in the flat panel display industry. Diamond films may also provide protection to surfaces in low Earth orbit where oxygen erosion is a problem. 

Saito Y, Seko K, Kinoshita Jl, Dynamic behavior of carbon nanotube field emitters observed by in situ transmission electron microscopy. Diamond and Related Materials, 2005. 14(11-12) 1843-1847. 

Dean, K., Chalamala, B., Coll, B., Talin, A., Trujillo, J., Wei, Y., Jaskie, J. - Fundamental properties of nanotube field emitters for large area electron sources . Sixth Applied Diamonds Conference/Second Frontier Carbon Technology, Auburn University, July 2001, NASA/CP-2001-210948... 

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