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-electronhole (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 < C nnp /C npp ≤ 12. This asymmetry is shown to limit the detection efficiency of Auger processes in our PL-based approach.

In situ reflectance-difference spectroscopy of doped CdTe and ZnTe grown by molecular beam epitaxy

Recent photoluminescence experiments presented by M. Binder et al. [Appl. Phys. Lett. 103, 071108 (2013)] demonstrated the visualization of high-energy carriers generated by Auger recombination in (AlInGa)N multi quantum wells. Two fundamental limitations were deduced which reduce the detection efficiency of Auger processes contributing to the reduction in internal quantum efficiency: the capture probability of these hot electrons and holes in a detection well and the asymmetry in type of Auger recombination. We investigate the transport and capture properties of these high-energy carriers regarding polarization fields, the capture distance to the generating well and the capture volume. All three factors are shown to have a noticeable impact on the detection of these hot particles. Furthermore, the investigations support the finding that electron-electronhole exceeds electron-hole-hole Auger recombination if the densities of both carrier types are similar. Overall, the results add to the evidence that Auger processes play an important role in the reduction of efficiency in (AlInGa)N based LEDs.

No abstract

No abstract

No abstract

Articles you may be interested inInvestigation of the crystallinity of N and Te codoped Zn-polar ZnO films grown by plasma-assisted molecularbeam epitaxy J. Appl. Phys. 108, 093518 (2010); 10.1063/1.3498800In situ reflectance-difference spectroscopy of doped CdTe and ZnTe grown by molecular beam epitaxy

No abstract