Title :
Study on photoemission mechanism for negative electron affinity GaN vacuum electron source
Author :
Qiao, J.L. ; Chang, B.K. ; Qian, Y.S. ; Wang, X.H. ; Li, Bing ; Fu, X.Q.
Author_Institution :
Sch. of Electron. Eng. & Optoelectron. Tech., Nanjing Univ. of Sci. & Technol., Nanjing, China
Abstract :
In this paper, the "three-step model" of photoemission mechanism for gallium nitride (GaN) photocathode is discussed. The first step is the absorption of incidence light. The incidence photon energy is absorbed by the electrons in the valence band, and this establishes the foundation that the electrons in the valence band are stimulated to the conduction band. The second step is the transportation of photoelectron, the excitated electrons in the conduction band will move from bulk to surface by diffusing or drifting.The third step of cathode photoemission is that the photoelectron passes through the surface potential.
Keywords :
III-V semiconductors; conduction bands; diffusion; gallium compounds; photoelectron spectra; photoemission; surface potential; wide band gap semiconductors; GaN; conduction band; diffusion; excitated electrons; incidence light absorption; negative electron affinity; photoelectron transportation; photoemission; photon energy; surface potential; three-step model; vacuum electron source; valence band; Gallium nitride;
Conference_Titel :
Vacuum Electron Sources Conference and Nanocarbon (IVESC), 2010 8th International
Conference_Location :
Nanjing
Print_ISBN :
978-1-4244-6645-0
DOI :
10.1109/IVESC.2010.5644315