Abstract The gradient-doping structure is first applied to prepare the transmission-mode GaAs photocathode and the integral sensitivity of the sealed image tube achieves 1420 μA/lm. This paper studies the inner carrier concentration distribution of the gradient-doping transmission-mode GaAs photocathode after molecular beam epitaxy (MBE) growth using the electrochemical capacitance-voltage profiling. The results show that an ideal gradient-doping structure can be obtained by using MBE growth. The total band-bending energy in the gradient-doping GaAs active-layer with doping concentration ranging from 1× 10 19 cm-3 to 1×1018 cm-3 is calculated to be 46.3 meV, which helps to improve the photoexcited electrons movement toward surface for the thin epilayer. In addition, by analysis of the band offsets, it is found that the worse carrier concentration discrepancy between GaAs and GaAlAs causes a lower back interface electron potential barrier which decreases the amount of high-energy photoelectrons and affects the short-wave response.
Received: 11 January 2009
Revised: 07 April 2009
Accepted manuscript online:
(Molecular, atomic, ion, and chemical beam epitaxy)
Fund: Project supported by the National
Natural Science Foundation of China (Grant Nos 60678043
and 60801036).
Cite this article:
Zhang Yi-Jun(张益军), Chang Ben-Kang(常本康), Yang Zhi(杨智), Niu Jun(牛军), and Zou Ji-Jun(邹继军) Distribution of carriers in gradient-doping transmission-mode GaAs photocathodes grown by molecular beam epitaxy 2009 Chin. Phys. B 18 4541
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Strain compensated type II superlattices grown by molecular beam epitaxy Chao Ning(宁超), Tian Yu(于天), Rui-Xuan Sun(孙瑞轩), Shu-Man Liu(刘舒曼), Xiao-Ling Ye(叶小玲), Ning Zhuo(卓宁), Li-Jun Wang(王利军), Jun-Qi Liu(刘俊岐), Jin-Chuan Zhang(张锦川), Shen-Qiang Zhai(翟慎强), and Feng-Qi Liu(刘峰奇). Chin. Phys. B, 2023, 32(4): 046802.
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