Simple physical model for the injection efficiency of diffused pn-junctions

The mechanism responsible for the injection efficiency of highly doped asymmetrical pn-junctions remains as one of the unanswered questions of pn-junction theory. To account for the experimentally measured injection ratio an extremely low lifetime must be assumed in the more highly doped region. This lifetime may be four to five orders of magnitude lower than that existing in the adjacent junction space-charge layer. The arbitrary assignment of a low lifetime to the heavily doped region has not been previously justified.