The photoconductive semiconductor switch (PCSS) is one of the most promising devices in pulsed power technology, and its transient output characteristics strongly depend on the internal photo-generated carrier transport. In this paper, the transient output characteristics of an opposed-contact GaAs PCSS are obtained at 3.0-5.35 kV at low-energy optical excitation. In contrast to the 8 ns optical pulse, the pulse width of the switching waveform is compressed to 2.2 ns, corresponding to a compression ratio of 72%. The electric field threshold of 38 kV/cm is verified for the pulse compression effect (PCE) in our experiment. The maximum output amplitude is 2.27 kV with a 660 ps rise time, and the relevant transmission efficiency is 43.7%. The transient electric field distribution of the GaAs PCSS at the bias voltage corresponding to the PCE is simulated by a two-dimension model. The influence of carrier transport on pulse compression is analyzed numerically during the spatiotemporal variation of the electric field. Results indicate that the PCE is attributed to the negative differential mobility (NDM) effect and the electric field shielding (EFS) effect. The characteristics of an ultrafast, compressed pulse, along with the increased output, provide the specific guidance for high-power applications at high repetition rates.

中文翻译：

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低能光激励下对置 GaAs 光电导开关的载流子传输和脉冲压缩

光电导半导体开关（PCSS）是脉冲功率技术中最有前途的器件之一，其瞬态输出特性强烈依赖于内部光生载流子传输。本文在低能光激励下，获得了在 3.0-5.35 kV 条件下对置接触 GaAs PCSS 的瞬态输出特性。与8 ns光脉冲相比，开关波形的脉冲宽度被压缩至2.2 ns，相当于72%的压缩率。在我们的实验中，验证了 38 kV/cm 的电场阈值的脉冲压缩效应 (PCE)。最大输出幅度为2.27 kV，上升时间为660 ps，相关传输效率为43.7%。通过二维模型模拟了PCE对应偏置电压下GaAs PCSS的瞬态电场分布。数值分析了电场时空变化期间载流子传输对脉冲压缩的影响。结果表明，PCE 归因于负微分迁移率 (NDM) 效应和电场屏蔽 (EFS) 效应。超快压缩脉冲的特性以及增加的输出为高重复率下的高功率应用提供了具体指导。