Reduced Dark-Current, Rise-Time, and On-State Delay of Avalanche GaAs Photoconductive Semiconductor Switches by Annealing-Grinding Process

In this letter, the performance of avalanche Gallium Arsenide (GaAs) Photoconductive Semiconductor Switch (PCSS) aimed at DC charging and fiber-triggered high-voltage switches (HVS) applications is reported. The optimal annealing condition suitable for the device is shown to be 250 °C for 30 min by studying the effects of different annealing conditions on the dark-state leakage current of the PCSS. Based on this, a novel annealing-grinding (AG) process is proposed to improve the electrical characteristics of GaAs PCSS. With an electrode gap of 10 mm and a bias voltage of 40 kV, the leakage currents of A-GaAs PCSS, G-GaAs PCSS and AG-GaAs PCSS are reduced by 60.6 %, 64 % and 67.8 %, respectively, compared with the literature. Further, the effects of different processes on the electrical pulse output of avalanche GaAs PCSS, such as optoelectronic delay time and rise time, are investigated. The results show that the avalanche GaAs PCSS can operate stably at 50 kV with a rising edge of 1.2 ns and a photoelectric delay time of 23.93 ns.