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

Current as high as 3.7 kA has been generated using a single photoconductive semiconductor switch (PCSS) excited by a laser pulse with the energy of similar to 8 mJ and under a bias of 28 kV. The PCSS with electrode gap of 14 mm 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 20 kV and 400 A. 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. (C) 2008 American Institute of Physics.