Velocity saturation characteristics of a V-doped 6H silicon-carbide (SiC) photoconductive switch under high electric field are presented. A vertical-geometry switch device based on vanadium-compensated SiC is triggered by a 532-nm laser pulse with light peak power of several hundred kW and operational voltages from 2 to 20 kV. The maximum electrical peak power achieved by the device is up to 1 MW (~50-A, 20-kV, 1.1-ns pulsewidth). When the working voltage is increased to increase output power, the carrier-velocity saturation under high electric field unavoidably impedes the current growth and directly limits the peak power. The parameters of parallel high-field-dependent mobility are obtained with different fields and laser energies: low-field mobility $\mu = 227 cm^{2}$ /V s and fitting parameter $\beta = 1.7$ . With working voltage increasing steadily, a crack-forming process results in device degradation as a result of large current and high electric field. The $I - V$ characteristic curves of the simulations and tests show current saturation and possible damage under high electric field.

中文翻译：

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高场速饱和度对 V 掺杂 6H 碳化硅光电导开关性能的影响

介绍了高电场下 V 掺杂的 6H 碳化硅 (SiC) 光电导开关的速度饱和特性。基于钒补偿 SiC 的垂直几何开关器件由 532 nm 激光脉冲触发，激光脉冲具有数百 kW 的光峰值功率和 2 至 20 kV 的工作电压。该器件实现的最大电峰值功率高达 1 MW（~50-A、20-kV、1.1-ns 脉冲宽度）。当提高工作电压以增加输出功率时，高电场下的载流子速度饱和不可避免地阻碍了电流的增长，直接限制了峰值功率。在不同场和激光能量下获得平行高场相关迁移率的参数：低场迁移率 $\mu = 227 厘米^{2}$ /V s 和拟合参数 $\beta = 1.7$ . 随着工作电压的稳定增加，大电流和高电场的形成过程会导致器件退化。这 $I - V$ 模拟和测试的特性曲线显示了在高电场下电流饱和和可能的损坏。