The low temperature behavior of thyristors

The forward breakover voltage (V/sub BF/) and forward conduction voltage drop of a thyristor have been measured as a function of decreasing temperature between 25 degrees C and -180 degrees C. The theoretical temperature dependence of the above parameters is derived and compared to the experimental results. The predicted fall of V/sub BF/ as temperature is decreased is primarily determined by the associated decrease in the avalanche breakdown voltage. The calculated and measured forms of V/sub BF/ generally show close correspondence, although the measured data show some deviation from the initial rate of linear fall at around -140 degrees C. At room temperature, all of the donor and acceptor atoms are ionized so that the donor/acceptor concentrations and carrier concentrations can be used interchangeably. As temperature is decreased, the above becomes an approximation, and the ionized donor/acceptor concentrations should strictly be used. At lower temperatures, the effective donor concentration decreases.<>