The Overvoltage LSA Relaxation Mode Study in Photoconductive Semiconductor Switch

The 11mm big gap semi-insulating(SI) GaAs photoconductive semiconductor switch (PCSS) is triggered by pulse laser, steady non-linear output waveforms are shown at 5kV~8kV bias voltage, the linear trend present when the bias voltage is higher than 9kV, the nonlinear Lock-on effect is gradually disappeared with the voltage increasing, eventually the pulse development into a complete linear waveform. Analysis that: the big gap SI-GaAs PCSS operate in higher than many times threshold voltage when switch satisfy 2×10⁴s.cm^-3≤n₀/f≤2×10⁵s·cm^-3 and n₀L≥10¹³cm^-2 conditions, switch work in overvoltage LSA(Limit Space charge Accumulate) relaxation mode.