中国物理B ›› 2017, Vol. 26 ›› Issue (1): 17804-017804.doi: 10.1088/1674-1056/26/1/017804
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
Hai-Juan Cui(崔海娟), Hong-Chun Yang(杨宏春), Jun Xu(徐军), Yu-Ming Yang(杨宇明), Zi-Xian Yang(杨子贤)
Hai-Juan Cui(崔海娟)1, Hong-Chun Yang(杨宏春)1, Jun Xu(徐军)1, Yu-Ming Yang(杨宇明)2, Zi-Xian Yang(杨子贤)1
摘要: An experimental study of leakage current is presented in a semi-insulating (SI) GaAs photoconductive semiconductor switch (PCSS) with voltages up to 5.8 kV (average field is 19.3 kV/cm). The leakage current increases nonlinearly with the bias voltage increasing from 1.2×10-9 A to 3.6×10-5 A. Furthermore, the dark resistance, which is characterized as a function of electric field, does not monotonically decrease with the field but displays several distinct regimes. By eliminating the field-dependent drift velocity, the free-electron density n is extracted from the current, and then the critical field for each region of n(E) characteristic of PCSS is obtained. It must be the electric field that provides the free electron with sufficient energy to activate the carrier in the trapped state via multiple physical mechanisms, such as impurity ionization, field-dependent EL2 capture, and impact ionization of donor centers EL10 and EL2. The critical fields calculated from the activation energy of these physical processes accord well with the experimental results. Moreover, agreement between the fitting curve and experimental data of J(E), further confirms that the dark-state characteristics are related to these field-dependent processes. The effects of voltage on SI-GaAs PCSS may give us an insight into its physical mechanism.
中图分类号: (Photoconduction and photovoltaic effects)