Towards quantification of the crucial impact of auger recombination for the efficiency droop in (AlInGa)N quantum well structures.

ABSTRACT

Recent experimental investigations on the reduction of internal quantum efficiency with increasing current density in (AlInGa)N quantum well structures show that Auger recombination is a significant contributor to the so-called "droop" phenomenon. Using photoluminescence (PL) test structures, we find Auger processes are responsible for at least 15 % of the measured efficiency droop. Furthermore, we confirm that electron-electron-hole (nnp) is stronger than electron-hole-hole (npp) Auger recombination in standard LEDs. The ratio of respective Auger coefficients is determined to be in the range 1 < Cnnp/Cnpp ≤ 12. This asymmetry is shown to limit the detection efficiency of Auger processes in our PL-based approach.