High-efficiency deep ultraviolet light-emitting diodes via δ-doping modulation of a thin p-GaN contact layer.

AlGaN-based light-emitting diodes (LEDs) operating in the deep-ultraviolet (DUV) spectral range have exhibited a promising future on physical sterilization. However, poor light extraction efficiency (LEE) and low Mg doping efficiency hinder the further pursuit of high-performance AlGaN-based DUV LEDs. Herein, we developed an improvement strategy for a highly efficient 278-nm AlGaN-based DUV LED via performing δ-doping modulation in a thin p-GaN contact layer. The δ-doping modulation can optimize the thin p-GaN ohmic contact layer via improving the Mg doping efficiency, thereby increasing the electrical and optical performances of the DUV LEDs. Consequently, with the assistance of the proposed δ-doping modulation, the peak light output power (LOP) of the DUV LED is improved by 34.1% in comparison to its referred counterpart with conventional-doped thin p-GaN, respectively. Our work is able to supply a new horizon in the development of the highly efficient AlGaN-based DUV emitters.