On the correlation of the Auger generated hot electron emission and efficiency droop in Ⅲ-N light-emitting diodes

摘要

Recent experiments presented in by Iveland et al. [Phys. Rev. Lett. 110, 177406 (2013)] demonstrated that hot electron emission from cesiated p-contacts of Ill-nitride quantum-well (QW) light-emitting diodes (LEDs) coincides with the onset of the efficiency droop. We have carried out Monte Carlo simulations of hot-electron transport in realistic Ⅲ-N LEDs. The simulations account for the hole population and all relevant electron scattering and recombination processes. We show that Auger recombination generates a significant hot electron population, which is temporarily trapped in the conduction band side-valleys, without decaying completely before reaching the p-contact. The leakage current due to electron overflow and thermal escape from the QWs is shown to have a minimal impact on the droop. We conclude that the experimentally observed hot electrons are created by Auger recombination in QWs, and that the Auger effect as the origin of the droop is the only consistent explanation for the experimental findings of Iveland et al., [Phys. Rev. Lett. 110, 177406 (2013)].