229 nm UV LEDs using p-type silicon for increased hole injection

TL;DR

This paper reports on 229 nm UV LEDs utilizing p-type silicon for enhanced hole injection, achieving high power and efficiency in deep UV emission with innovative contact design.

Contribution

Introduction of p-type silicon nanomembrane contacts to significantly improve hole injection in deep UV AlGaN LEDs, enabling higher power and efficiency.

Findings

No efficiency droop up to 76 A/cm2

160 μW optical power achieved

External quantum efficiency of 0.027%

Abstract

Ultraviolet (UV) light emission at 229 nm wavelength from diode structures based on AlN/Al0.77Ga0.23N quantum wells and using p-type Si to significantly increase hole injection was reported. Both electrical and optical characteristics were measured. Owing to the large concentration of holes from p-Si and efficient hole injection, no efficiency droop was observed up to a current density of 76 A/cm2 under continuous wave operation and without external thermal management. An optical output power of 160 uW was obtained with corresponding external quantum efficiency of 0.027%. This study demonstrates that by adopting p-type Si nanomembrane contacts as hole injector, practical levels of hole injection can be realized in UV light-emitting diodes with very high Al composition AlGaN quantum wells, enabling emission wavelengths and power levels that were previously inaccessible using traditional p-i-n structures with poor hole injection efficiency.