Improved efficiency of near-ultraviolet LEDs using a novel p-type AlGaN hole injection layer

• We enhanced the optical power of near-ultraviolet LED by using pAlGaN hole injection layer.
• The Al-gradual pAlGaN layer could further improve the light efficiency of near-ultraviolet LED.
• The light power of near-ultraviolet LED with Al-gradual pAlGaN layer increase by 266%.

We investigate a novel near-ultraviolet light-emitting diode (NUV-LED) with a p-type AlGaN (pAlGaN) hole injection layer to replace the conventional p-type GaN layer. The optical properties are studied numerically with simulations. Our calculated results indicate that a pAlGaN layer can significantly improve both light output power and internal quantum efficiency of a NUV-LED. The light power of NUV-LED with constant and gradually increasing Al content of the pAlGaN layer increases by 215% and 266% compared to a conventional LED. We also find that the elimination of the interface barrier and suppression of the polarization field are the key factors that lead to the improved NUV-LED performance.