Cryogenic operation of p-i-n power rectifiers

Detailed measurements and modeling results for 1200-V p-i-n diodes over the temperature range 300-77 K are presented. At typical rated current levels, the forward voltage drop increases with a decrease in temperature. Analysis and measurements show that there is an order-of-magnitude reduction in the i-region stored charge from 300 to 77 K. This results in greatly reduced switching losses at 77 K. An analytical model including end region recombination with bandgap narrowing is presented to explain the experimental observations.