High-Power Semi-Insulating GaAs Photoconductive Semiconductor Switch Employing Extrinsic Photoconductivity

A photoconductive semiconductor switch (PCSS) with a gap of 0.018 m was fabricated from semi-insulating GaAs. Illuminated by a laser pulse with varying optical energies at a wavelength of 1064 nm, the photoconductivity tests of the PCSS were performed at different bias voltages. In nonlinear mode, by comparing the charge initially stored in the capacitors and the charge through the switch, it is found that the end of lock-on phase is not always due to the fact that the energy has been dumped from the charging system. The threshold of incident optical energy and the ON-state resistance are analyzed and calculated. The PCSS failed at a bias voltage of 32 kV because of surface flashover.