Strategically constructed AlGaN doping barriers for efficient deep ultraviolet light-emitting diodes

Here, we propose a sandwich -like Si -doping scheme (undoped/Si-doped/undoped) in Al 0. 6 Ga 0. 4 N quantum barriers (QBs) to simultaneously promote the optoelectronic performances and reliability of deep ultraviolet light-emitting diodes (DUV-LEDs). Through experimental and numerical analyses, in the case of DUV-LEDs with conventional uniform Si -doping QB structure, severe operation-induced reliability degradation, including the increase of reverse leakage current ( I R ) and reduction of light output power (LOP), will offset the enhancement of optoelectronic performances as the Si -doping levels increase to an extent, which hinders further development of DUV-LEDs. According to a transmission electron microscope characterization and a numerical simulation, an improved interfacial quality in multiple quantum wells (MQWs) and more uniform carrier distribution within MQWs are demonstrated for our proposed Si -doping structure in comparison to the uniform Si -doping structure. Consequently, the proposed DUV-LED shows superior wall-plug efficiency (4%), I R at -6 V reduced by almost one order of magnitude, and slower LOP degradation after 168-h 100 mA-current-stress operation. This feasible doping scheme provides a promising strategy for the high-efficiency and cost-competitive DUV-LEDs. (c) 2024 Optica Publishing Group