Electrical Properties of Optically Triggered SiC JFET for Power Electronic Application

A novel high voltage optically triggered SiC Junction Field Effect Transistor (JFET) configuration is proposed. The electrical and switching characteristics of the device is studied theoretically by solving the experimentally validated transport and physical models and do analysis experimentally. The optical signal trigger low-voltage optically controlled GaAs switch, called optically triggered power transistor (OTPT), is designed for voltage rating of nearly 70 V. The OTPT is connected in series with normally-on SiC JFET to handle the current switching. The simulation result found that the optically triggered SiC JFET operated with very high blocking voltage of 1200 V and rate of current rise (di/dt) of 25 A/ns at 500 V drain bias with significantly low leakage current of 10 μA. Additionally, it is found that the current of the optically triggered JFET increases with the increase of optical power of illuminated laser. Furthermore, the experimental outcome of turn on and turn off time of the device studied at comparatively low drain bias (200 V) are 95 nm and 740 ns respectively. Finally, very high breakdown voltage and high rate of current rise leads the SiC optical JFET a potential candidate for high power switching application.