Experimental investigation on lifetime of high power GaAs photoconductive semiconductor switch

Photoconductive semiconductor switch(PCSS) with a gap of 18 mm was fabricated from semi-insulating GaAs. Lifetime tests of the PCSS were performed at different repetition rate. Accumulation and dissipation of heat in the switch’s running process was analyzed with the test results. Heat accumulation has an important effect on the lifetime of the switch. When the accumulation power of heat is higher than the dissipation power of heat, the temperature of the chip rises and the resistence reduces. As a results, the leak current increased as high as the charge current of the capacitor and the switch can’t sustain a bias voltage, and the photocurrent decreases as the switch is running. In addition, the damage at the ohm contact is also a heat damage because of a high field at the electrode reg