Performance Enhancement of Planar GaAs Photoconductive Semiconductor Switches by Introducing p-Type Epitaxial Layer

Gallium arsenide photoconductive semiconductor switches (GaAs PCSSs) have attracted much attention in pulsed power systems and high-power microwave sources. The quality of ohmic contact has a significant impact on their switching performance. In this article, a 100 nm p-type epitaxial layer and Ti/Pt/Au metal electrodes were introduced into a GaAs PCSS to enhance ohmic contact, resulting in a specific contact resistivity of 3 × 10−4 Ω·cm2. The optimized device exhibited a reduction in dark current from 32.2 μA to 11.7 μA and achieved a peak pulse output of 4 kV under a bias of 8.1 kV. This work provides a new feasible approach for high-power miniaturized solid switches.