中国物理B ›› 2009, Vol. 18 ›› Issue (10): 4515-4520.doi: 10.1088/1674-1056/18/10/069

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Transient surface photoconductivity of GaAs emitter studied by terahertz pump-emission spectroscopy

施宇蕾, 周庆莉, 张存林   

  1. Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 China
  • 收稿日期:2009-03-09 修回日期:2009-04-07 出版日期:2009-10-20 发布日期:2009-10-20
  • 基金资助:
    Project supported by the National Basic Research Program (973 Program) (Grant Nos 2007CB310408 and 2006CB302901), the National Natural Science Foundation of China (Grant No 10804077), and Funding Project for Academic Human Resources Development in Institu

Transient surface photoconductivity of GaAs emitter studied by terahertz pump-emission spectroscopy

Shi Yu-Lei(施宇蕾), Zhou Qing-Li(周庆莉)†, and Zhang Cun-Lin(张存林)   

  1. Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048,  China
  • Received:2009-03-09 Revised:2009-04-07 Online:2009-10-20 Published:2009-10-20
  • Supported by:
    Project supported by the National Basic Research Program (973 Program) (Grant Nos 2007CB310408 and 2006CB302901), the National Natural Science Foundation of China (Grant No 10804077), and Funding Project for Academic Human Resources Development in Institu

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摘要： This paper investigates the ultrafast carrier dynamics and surface photoconductivity of unbiased semi-insulating GaAs in detail by using a terahertz pump-emission technique. Based on theoretical modelling, it finds that transient photoconductivity plays a very important role in the temporal waveform of terahertz radiation pulse. Anomalous enhancement in both terahertz radiation and transient photoconductivity is observed after the excitation of pump pulse and we attribute these phenomena to carrier capture in the EL2 centers. Moreover, the pump power- and temperature-dependent measurements are also performed to verify this trapping model.

Abstract: This paper investigates the ultrafast carrier dynamics and surface photoconductivity of unbiased semi-insulating GaAs in detail by using a terahertz pump-emission technique. Based on theoretical modelling, it finds that transient photoconductivity plays a very important role in the temporal waveform of terahertz radiation pulse. Anomalous enhancement in both terahertz radiation and transient photoconductivity is observed after the excitation of pump pulse and we attribute these phenomena to carrier capture in the EL2 centers. Moreover, the pump power- and temperature-dependent measurements are also performed to verify this trapping model.

Key words: terahertz, ultrafast carrier trapping, surface photoconductivity

中图分类号:  (Surface conductivity and carrier phenomena)

  • 73.25.+i
72.20.Jv (Charge carriers: generation, recombination, lifetime, and trapping) 72.40.+w (Photoconduction and photovoltaic effects) 72.80.Ey (III-V and II-VI semiconductors) 78.70.Gq (Microwave and radio-frequency interactions)