Experimental study of semi-insulating GaAs photoconductive semiconductor switch

A single photoconductive semiconductor switch with electrode gap of 18mm was fabricated from semi-insulating GaAs, of which the most notable defect was EL2. Photoconductivity tests were performed using 1064nm wavelength laser pulse. The PCSS began to work in the nonlinear mode at 10kV with the laser energy of 10.6mJ. The highest photocurrent tested for 11.4mJ optical excitation at the bias voltage of 20.5kV was ~2kA. A resistance of 20.7Ω was in series with the PCSS to limit the loop current because the max current Rogowski coil can measure was 2kA. Hold-off voltage tests were performed. The PCSS failed at a bias voltage of 32kV because of surface flashover.