30 kV and 3kA semi-insulating GaAs photoconductive semiconductor switch

Abstract

Current as high as 3.7kA has been generated using a single photoconductive semiconductor switch (PCSS) excited by a laser pulse with the energy of ∼8mJ and under a bias of 28kV. The PCSS with electrode gap of 14mm was fabricated from semi-insulating GaAs. Under different bias voltages the “on” resistances of the PCSS were measured. The longevity of the PCSS reached 350 shots at 20kV and 400A. The breakdown mechanism of the PCSS is analyzed based on the breakdown characteristics. It is shown that the breakdown of GaAs PCSS can be described by the electron-trapping breakdown theory.