采用高质量半绝缘碳化硅(SiC)单晶材料制作了超快高耐压大功率SiC光电导开关。应用氟化氪准分子脉冲激光器作为激发光源,得到了脉宽为40 ns,上升沿为9.6 ns 的超快响应的电脉冲,开关的上升沿存在两个不同阶段。测试开关两端电压从1 kV到10 kV时开关导通的电压波形表明,开关的导通电阻随电压的增加不发生明显变化,开关在导通态时导通电阻在12 Ω左右。采用92 Ω精密电阻作为负载,计算得到开关两端外加11 kV电压时通过其电流峰值高达159 A,此时峰值功率达到1.4 MW,在此范围内未出现载流子饱和现象。

A high-power photoconductive semiconductor switch(PCSS) has been fabricated by semi-insulating silicon carbide crystal. The width of the output voltage pulse was about 40 ns and the rise-time was 9.6 ns,when a KrF excimer laser was adopted as the excitation source. Two different steps were observed in the rising edge. With the input voltage rising from 1 kV to 11 kV,the on-state resistance remained about 12 Ω. The peak current through the PCSS came to be 159 A with the 11 kV input voltage,while the peak power reached 1.4 MW. No carrier saturation has been observed in the experiment.