GaAs光导开关耐压试验研究

Research on withstand voltage experiment of GaAs photoconductive switch

对设计制作的3mm间隙共面型GaAs光导开关进行了耐压试验研究。试验中比较了光导开关的静态绝缘电阻、暗电流和击穿电压之间的关系,发现在1 kV时暗电流不高于3μA的光导开关在试验中击穿电压都在12 kV左右,这为试验前评价光导开关的耐压性提供了参考依据。采用不同方式对光导开关进行了绝缘保护,并结合介质击穿理论对试验结果进行了分析,结果表明:绝缘保护可以有效提高耐压特性,绝缘强度达4 kV/mm。

The withstand voltage experiments are done with fabricated 3mm gap coplanar electrodes GaAs photoconductive semiconductor switch（PCSS）. The comparison between static insulation resistance,dark-current and withstand voltage are analyzed, and results show if a PCSS dark-current is less than or equal to 3 μA at 1 kV DC, the breakdown voltage in experiment is about 12 kV, and this conclusion provides a reference for evaluating the voltage resistance of PCSS before withstand voltage experiments. Different insulation technique for surface protection of high-voltage are tested and different protection materials are coated on the surface of the GaAs switch. Combined with medium insulation and the surface breakdown theory, the experiment data are analyzed. The theoretical study and experiment results show that approriate insulation technique can improve the voltage resistance of GaAs PCSS efficiently ,and the hold-off field strength reaches 4 kV/mm.