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

Abstract

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.

Optimizing performance and energy consumption in GaN(n)/In x Ga 1- x N/GaN/AlGaN/GaN(p) light emitting diodes by quantum-well number and mole fraction

“…Figure 1 schematically describes the simulated MQW LED structure that involves GaN(n)/InxGa1-xN/GaN/AlGaN/GaN(p). Earlier studies, dealing with MQW structures were reported describing other aspects of the LED devices using the Atlas-Silvaco [40,42]. In the present study, a 3000 nm thick n-GaN layer is used.…”

“…Therefore, simulation studies, using SilvacoTcad program [36], Matlab [37], Sentaurus [38] and Comsol metaphysics [39], were made. In fact, simulation helps understand the effects of various phenomena, such as radiative phenomena [40] and the band offset in quantum wells and barriers [41] on diode structures, optical properties and performance, while avoiding high production costs.…”

Efficient Carrier Confinement in AlGaN‐Based Deep‐Ultraviolet Light‐Emitting Diodes with a Composition‐Graded Electron‐Blocking Layer

“…[ 29 ] In addition, the optical recombination rate, Auger recombination coefficient, and Shockley–Read–Hall (SRH) recombination lifetime of electrons and holes are 10 −11 cm 3 s −1 , 2.88 × 10 −30 cm 6 s −1 , and 15 ns, respectively. [ 30,31 ] Second, considering the self‐shielding effect caused by the defect misalignment of the AlN template at the bottom of the actual DUV LED and the effect of interface charge compensation on the optical output power, the polarization effect was set as 50% of the total charge (there are more material parameters that were employed in the simulation. [ 32 ] ).…”