High-power gaas photoconductive semiconductor switches triggered by a laser diode

Abstract

Photoconductive Semiconductor Switches (PCSSs) are potential in generation of high-power impulse due to the unique performance compared with traditional high-power pulsed devices. Gallium arsenide (GaAs) photoconductive semiconductor switch is regarded as a promising pulse-power device for the outstanding properties, such as simple structure, low optical trigger energy, low timing jitter, high breakdown voltage, and large current1–4. High-power PCSSs with a gap of 0.562mm were fabricated from semi-insulating GaAs, in which carbon acceptor impurity was compensated by deep EL2 donor defect, resulting in very large dark resistivity. The PCSS operate in a nonlinear mode, and obtained a 998 A large current under a bias voltage of 1.45 kV when the PCSS was triggered by a 4-μJ commercial laser diode. And the PCSS is opposed contact structure instead of lateral structure in our experiment. The breakdown mechanism and lifetime of high power GaAs PCSS are brief analyze. Meanwhile, initial experimental results of the PCSSs under different field intensity and capacitance will be presented. An overview of the PCSS characteristics and the attractive prospect of a low-cost compact high-power pulse source with the high power GaAs PCSS will be presented.