Investigation on the Mechanism of Triggering Efficiency of High-Power Avalanche GaAs Photoconductive Semiconductor Switch

In this letter, the triggering efficiency of 1-mm-gap, opposed-contact GaAs Photoconductive Semiconductor Switch (PCSS) is studied in avalanche mode. Compared with the anode-triggered PCSSs, it is found that the cathode-triggered devices are with shorter delay time and lower on-state resistance under the same operation conditions. The delay time jitter of ~45.6 ps is also achieved at the power level of
$\sim 4$
MW by cathode triggering. Then the theory of multiple avalanche domains is introduced to interpret the influence of laser spot location on triggering efficiency by a two-dimensional (2D) device simulation. The delay time and on-state resistance are essentially attributed to the formation time and the density of avalanche domains which are affected by the triggering position.