Popis: |
The forward voltage of thyristors in the fired state is discussed from points of view which are especially relevant for power thyristors. With big forward currents, i.e. with high level injection in both base regions, the forward voltage of a thyristor should become identical with that of a pin rectifier of equal dimensions. This is verified by experiment; it is furthermore shown that the forward voltage is independent of the doping level in the base regions. For the difference of the forward voltages of both devices found with low current densities a simple approximate relation is derived and substantiated by experiment. The carrier lifetime with high injections is found to be independent of the doping level in these experiments; this was affirmed, too, by former measurements. |