Effects of vanadium-compensated concentration on the electrical characteristics of 6H-SiC photoconductive semiconductor switches

By means of two-dimensional device simulator, the effects of vanadium-compensated concentration on the electrical characteristics of 6H SiC photoconductive semiconductor switches (PCSS) are explored. In the simulator, the model of PCSS is an n-type device doped with 1×1014cm−3, and is compensated by vanadium (V). Under a bias of 1500 V, the dark current in case of V-concentration of 1×1012cm−3is 1 A, and decreased to 5×10−7A for V-concentration of 1×1015cm−3. Illuminated by 0.4 um incident light with a power of 2500 W/cm−2, the peak current in case of V-concentration of 1×1012cm−3is 160 A, and decreased to 6 A for V-concentration of 1×1015cm−3. The spectral responsivity of 6H SiC PCSS is maximized in 0.3875 um with a value of 4.8 mA/W under a bias of 1500 V. From the results, the V-concentration should be chosen to achieve the insulation characteristics and photocurrent according to the doped concentration.