Performance improvement of AlGaN-based deep-ultraviolet light-emitting diodes via Si-doping design of quantum barriers

Characteristics of AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) with light-emitting wavelength around 265 nm by adopting different Si-doping design of the last quantum barrier (LQB) have been investigated. Simulation approach yields a result that, the light output power (LOP) and internal quantum efficiency (IQE) of sample with the completely undoped LQB are both improved compared to cases of fully doping and step-doping of the LQB structures. The key factors for the performance improvement are decrease of average electric field strength within the last quantum well layer and increase of the effective barrier height for electrons, and thereby reducing the leakage of electrons and then improving the radiative recombination rates, which suggests that keeping the LQB undoped is of great potential for design and application of high-efficiency AlGaN-based DUV LEDs.