High temperature performance of high-power GaAs Schottky and silicon p-i-n rectifiers in hard- and soft-switching power converters

The dynamic switching characteristics of 200 V high-power GaAs Schottky and Si p-i-n rectifiers are studied at various temperatures under both hard and soft switching conditions. Devices were first characterized to measure forward and reverse I-V, C-V, reverse breakdown voltage and reverse recovery performances. The same devices were characterized for turn-on and turn-off in switching circuits designed to study the dynamic switching performances under hard and soft switching conditions at different temperatures. Advanced finite element based mixed device and circuit simulations were used to study the internal plasma dynamics under boundary conditions imposed by circuit operation. It is shown that, for hard switching applications, GaAs Schottky power rectifiers exhibit significantly reduced switching power losses compared to Si p-i-n rectifiers. For soft switching applications, there is no significant difference in the switching power losses for these two devices. Diode performance at elevated temperatures is studied and the temperature dependencies of switching and conduction power losses are analyzed.