Study of the effective grain boundary recombination velocity under different injection levels

The recombination activity of a grain boundary, is usually expressed by an effective recombination velocity s
eff
defined at the grain boundary depletion layer edge. While theory shows that s
eff
decreases with increasing injection levels, experiments however could not clearly confirm this theoretical expectation. In this letter a new method to measure s
eff
as a function of the injection level is proposed. Using this method, strong direct experimental evidence for a decreasing s
eff
with the injection level is given.