1. Institute of Electronic Engineering and Optoelectronic Technology, Nanjing University of Science and Technology, Nanjing 210094, China 2. Department of Electronic and Electrical Engineering, Nanyang Institute of Technology, Nanyang 473004, China
Abstract：For a quantitative analysis of the effect of varied doping structure on the quantum efficiency of cathode, two kinds of reflective gradient doping GaAs photocathode samples were designed and grown respectively. After activation, the dynamic spectral response curves of the two samples were obtained. The spectral response curves were transformed into quantum efficiency curves. The quantum efficiency curves in different wavebands were fit，and the varied doping coefficient K that reflects the contribution of the varied doping structure to the cathode quantum efficiency was obtained. Results show that, the functional effects of the same material varied doping structure responding to the incident photon of different wavebands are different from each other. The same is true for the different material varied doping structures responding to the same waveband incident photon. The fundamental reasons for these differences are that the positions and the intensities of the inside electric fields which build within the materials under different varied doping structures are different from each other. It offers an effective analysis means to evaluate the structure performance of cathodes grown under different doping ways, and has great value for the study on optimization design of cathode varied doping structure.
Key words：GaAs photocathode;Varied doping;Built-in electric field;Quantum efficiency
[1] Mulhollan G A, Subashiev A V, Clendenin J E, et al . Phys. Lett. A, 2001, 282: 309. [2] Drouhin H J, Hermann C, Lampel G. Phys. Rev. B, 1985 , 31(6): 3859. [3] Su C Y, Lindau I, Spicer W E. Chem. Phys. Lett., 1982, 87(6): 523. [4] Su C Y, Spicer W E, Lindau I. J. Appl. Phys., 1983, 54(3): 1413. [5] DU Xiao-qing, CHANG Ben-kang, ZOU Ji-jun(杜晓晴, 常本康, 邹继军, 等). Acta Optica Sinica(光学学报), 2005, 25(10): 1411. [6] ZOU Ji-jun, CHANG Ben-kang, YANG Zhi(邹继军，常本康，杨 智). Acta Physica Sinica(物理学报)，2007，56(5): 2992. [7] Zou Jijun, Chang Benkang. Optical Engineering, 2006, 45(5): 054001. [8] ZOU Ji-jun, CHANG Ben-kang, DU Xiao-qing, et al(邹继军, 常本康, 杜晓晴, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2007, 27(8): 1465. [9] Chang Benkang, Du Xiaoqing, Liu Lei, et al. Proc. SPIE, 2003, 5209: 209. [10] ZONG Zhi-yuan, QIAN Yun-sheng, CHANG Ben-kang. Proc, SPIE, 2001, 4580: 623. [11] QIAN Yun-sheng, ZONG Zhi-yuan, CHANG Ben-kang(钱芸生, 宗志园, 常本康). Vacuum Science and Technology(真空科学与技术), 2000, 20(5): 305. [12] ZOU Ji-jun, CHANG Ben-kang, YANG Zhi, et al(邹继军, 常本康, 杨 智, 等). Acta Physica Sinica(物理学报), 2007, 56(10): 6109. [13] LIU Yuan-zhen, WANG Zhong-chun, DONG Ya-qiang(刘元震, 王仲春, 董亚强). Electron Emission and Photocathode(电子发射与光电阴极). Beijing: Beijing University of Science and Technology Press(北京: 北京理工大学出版社), 1995. 308. [14] ZOU Ji-jun, CHEN Huai-lin, CHANG Ben-kang, et al(邹继军, 陈怀林, 常本康, 等). Acta Optica Sinica(光学学报), 2006, 26(9): 1400.
