Improved Performance of InGaN/AlGaN Multiple-Quantum-Well Near-UV Light-Emitting Diodes with Convex Barriers and Staggered Wells

The physical mechanism of improving the photoelectric performance of InGaN/AlGaN-based near UV light-emitting diode (LED) with convex quantum barrier and staggered quantum well (QW) is studied by numerical simulation. The simulation results indicate that the voltage-current characteristics of the LED structure with convex quantum barrier and staggered QW are effectively improved compared with the traditional multiple quantum well (MQW) structure, and its electroluminescence (EL) intensity and light output power are significantly improved. The main physical mechanisms are: on the one hand, the convex quantum barrier with a lower average Al component can reduce the polarization electric field at the interface between the quantum barrier and QW as well as the effective potential barrier of holes, improve the spatial separation of electron and hole wave functions, promote the injection efficiency of carriers, and improve the uniformity of carrier distribution in the MQWs active region; On the other hand, staggered QWs can provide stronger carrier confinement effect and further increase the overlap of electron and hole wave functions, so as to improve the carrier radiative recombination efficiency; In a word, this work provides a valuable reference for obtaining high-performance near-ultraviolet LED.