| The structure, working mechanism, dark-state and transient characteristics of SiC photoconductive switch are studied in detail. This paper emphasizes the simulation and analysis on the characteristics of SiC PCSS under the influences of the substrate material doping concentration, trap concentration, optical pulse and applied voltage.Vanadium compensated n-type 6H-SiC PSCC horizontal structure model is established with the total horizontal width of 150μm, electrode width of 30μm and the vertical thickness of 15μm. When the trap concentration of 1×1015cm-3, dark resistance is about 3×106?, and it is 104 times larger than that of the PCSS dark resistivity with trap concentration of 1×1014cm-3. SiC PCSS dark state characteristics can be effectively improved by introducing the concentration of trapsCurrent pulse rise time is only 1.06ns and fall time is about 1.56ns. In addition to the role of compensation to achieve semi-insulating material, there are restrictions on mobility, carrier lifetime and so on. Therefore, the value of trap concentration plays a significant role to improve the work performance of PCSS. Devices work in the intrinsic absorption model, so according to Bohr frequency, the energy of incident light must be greater than the band gap to get effective photocurrent.With increasing the size of SiC photoconductive switch, the area is 1000μm×450μm, and the electrode is 100μm. When the wavelength and wave power of the optical is 300nm and 300W/cm2, the peak current is up to 25.1A/μm under 50V applied voltage. The current pulse rise time is about 4.2ns, and fall time is about 8.62ns. In order to make high-speed photoconductive switch, the electrode spacing need to be reduced and the applied voltage need to be increased.This paper also discusses how to increase output power, how to optimize the turn-off characteristics, how to make high-quality ohmic contact electrode and so on.
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