High efficiency GaN-based near UV light emitting diodes with asymmetric triangular multiple quantum wells

Abstract

Near-ultraviolet (NUV) light-emitting diodes (LEDs) have found many applications in the areas such as UV curing, bio-chemical sensors etc. However, the internal quantum efficiency (IQE) of NUV-LEDs show relatively lower value than blue LEDs. In previous research, asymmetric triangular MQWs with gallium face-oriented inclination in the blue wavelength band are demonstrated to have higher emission efficiency and lower efficiency droop. In this study, we surprisingly found different trend in NUV-LEDs. Compared to blue LEDs, NUV-LEDs tend to have shallower quantum wells and less ability to localize holes. In the simulation results, holes are more confined within nitrogen face-oriented inclination than that in MQWs with gallium face-oriented inclination and the IQE are improved about 10%.