Evidence for trap-assisted Auger recombination in MBE grown InGaN quantum wells by electron emission spectroscopy

TL;DR

This study uses electron emission spectroscopy to investigate hot electron generation in InGaN quantum wells, suggesting trap-assisted Auger recombination as a key process affecting LED efficiency.

Contribution

It provides direct evidence of hot electrons in InGaN quantum wells, indicating trap-assisted Auger recombination as a significant non-radiative process.

Findings

Hot electrons detected in InGaN quantum wells.

Efficiency losses likely due to trap-assisted Auger recombination.

External quantum efficiency remains below 1% without droop.

Abstract

We report on the direct measurement of hot electrons generated in the active region of blue light-emitting diodes grown by ammonia molecular beam epitaxy by electron emission spectroscopy. The external quantum efficiency of these devices is <1% and does not droop; thus, the efficiency losses from the intrinsic, interband, electron-electron-hole, or electron-hole-hole Auger should not be a significant source of hot carriers. The detection of hot electrons in this case suggests that an alternate hot electron generating process is occurring within these devices, likely a trap-assisted Auger recombination process.