Nearly Efficiency-Droop-Free AlGaN-Based Deep-Ultraviolet Light-Emitting Diode Without Electron-Blocking Layer

An aluminum-rich AlGaN layer is commonly implemented to act as an electron-blocking layer (EBL) to block electron overflow from the active region in the conventional deep-ultraviolet light-emitting diodes (DUV LEDs). Herein, we propose a DUV LED device architecture with specially designed band-engineered quantum barriers (QBs) to “serve” as an alternative approach to alleviate such overflow effect, suppressing the electron leakage, and facilitating the electron and hole injection into the active region for efficient radiative recombination. Intriguingly, a much smaller efficiency droop with a significant enhancement of light output power (LOP) by nearly 50% can be achieved at the injection current level of 120 mA in such EBL-free device, in comparison with the conventional EBL-incorporated DUV LED structure. Thus, the EBL-free device architecture provides us an alternative path toward the realization of efficient DUV light emitters.