高压超大电流光电导开关及其击穿特性研究

研制了耐压达32 kV，通态峰值电流达3.7 kA的高压超大电流半绝缘GaAs光电导开关.分析了光电导开关在强场下的击穿机理，指出对于间接能带间隙光导材料(如Si)制作的光电导开关，开关的击穿电压主要由陷阱填充限制电导模型决定.而对于直接能带间隙光导材料(如GaAs,InP等)制作的光电导开关，开关击穿主要是由开关体负阻效应在开关阳极产生的空间电荷累积所导致的开关阳极电场剧增引起的.基于转移电子效应对GaAs光电导开关击穿电压进行了理论计算，计算结果与实验相一致. 关键词： 光电导开关 击穿 转移电子效应 陷阱填充

A high-voltage and high-current photoconductive semiconductor switch and its breakdown characteristics

Semi-insulating GaAs photoconductive semiconductor switch (PCSS) with withstand voltage of 32 kV and peak current of 3.7 kA has been developed. The breakdown mechanism of the PCSS is analyzed. It is shown that the breakdown of PCSS fabricated from indirect band-gap semiconductors is determined mainly by limited conduction of trap filling, but for PCSS's fabricated from materials that exhibit the transferred-electron effect, such as GaAs, breakdown of the PCSS is caused mainly by the negative-resistance-induced electric field enhancement at the anode boundary. Based on the Gunn effect electronics, the breakdown voltage of the semi-insulating GaAs PCSS is calculated, and the calculated results agree with the experimental results.