Density-activated defect recombination as a possible explanation for the efficiency droop in GaN-based light emitters

The droop of the internal efficiency in GaN-based light emitting devices reflects a carrier loss mechanism that has a stronger dependence on the intrinsic carrier density than the about quadratic dependence of the radiative recombinations. Here we discuss density-activated defect recombination (DADR) (Hader et al., 2010) as a possible source for this non-radiative loss at least for the low to medium density regime.