Enhanced Internal Quantum Efficiency of Bandgap-Engineered Green W-Shaped Quantum Well Light-Emitting Diode

Abstract

To improve the internal quantum efficiency of green light-emitting diodes, we present the numerical design and analysis of bandgap-engineered W-shaped quantum well. The numerical results suggest significant improvement in the internal quantum efficiency of the proposed W-LED. The improvement is associated with significantly improved hole confinement due to the localization of indium in the active region, leading to improved radiative recombination rate. In addition, the proposed device shows reduced defect-assisted Shockley-Read-Hall (SRH) recombination rate as well as Auger recombination rate. Moreover, the efficiency rolloff in the proposed device is associated with increased built-in electromechanical field.

Review—A Survey of Simulations on Device Engineering of GaN-Based Light-Emitting Diodes

“…Usman et al have numerically investigated zig-zag-shaped QWs in comparison to rectangular QWs by using the APSYS simulator. 61 They report 3 nm thick QWs with composition grading of indium as 32%-28%-32%-28%-32%, as shown in Fig. 6a.…”

Performance of Improvement of AlGaN‐Based Deep UV Light‐Emitting Diode with Two Parts Linearly Graded Barriers

“…[17] Li et al proposed the Trapezoidal lectron blocking layer and Liu et al proposed the stepped super-lattice electron blocking layer. [18,19] Besides, articles on QW structures have been widely published in recent years: graded quantum QWs/QBs; [20,21] varying trapezoidal bottom well width [22] ; staggered InGaN QWs; [23][24][25] zigzag QWs and W-shaped QWs; [26,27] and step-stage multiple quantum well (MQW). [28] Of course, some strategies for regulating band of QB have been reported to ameliorate polarized electric field in MQWs and reduce the quantum-confined stark effect (QCSE) to improve internal quantum efficiency: for example, inserting single spike barriers [29] ; graded Al-content AlGaN insertion layer; [30] partially graded QBs; [31] linear increment of Al composition by 0.03 along the growth direction in DOI: 10.1002/pssa.202300276 Herein, a novel AlGaN-based multiple quantum well (MQW) deep UV lightemitting diode (DUV-LED) structure with two parts linearly graded barriers is presented.…”

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

“…Up to now, some strategies for regulating band of QW and quantum barrier have been reported to ameliorate polarized electric field in MQWs active region and reduce the quantum confined stark effect for increasing the overlap of electron and hole wave functions: such as dual‐layer staggered quantum barrier with the graded Al composition, [ 17 ] three‐layer staggered quantum barrier, [ 18 ] dual‐triangle quantum barriers, [ 19 ] stepped quantum barrier with the graded In composition, [ 20,21 ] concave quantum barrier, [ 22 ] partial‐grade barriers, [ 23 ] InGaN barriers, [ 24 ] adjusting the width of QWs or barriers [ 25,26 ] ; Besides, many proposals for optimizing QW structure have been reported: triangular QWs, [ 27 ] staggered InGaN QWs, [ 28–31 ] gradually varying indium content QWs, [ 32 ] trapezoidal QWs, [ 33,34 ] step‐stage QWs, [ 35 ] zigzag‐shaped QWs, [ 36 ] and W‐shaped QWs. [ 37 ] This method uses a variety of ways for designing the energy band of QWs and barriers to ameliorate carrier transport and distribution as well as to obtain a marked advanced radiative recombination rate. However, especially in the research of NUV LED, the research cases of adjusting the energy band of QW and quantum barrier at the same time are rarely reported.…”