Improvement in efficiency and luminous power of AlGaN-based D-UV LEDs by using partially graded quantum barriers

Research Progress and Development Prospects of Enhanced GaN HEMTs

“…With the emergence of the wide bandgap semiconductor materials, GaN-based semiconductor materials and their multi-component alloy compounds showed excellent optical, electrical, chemical, physical and other properties, which has become the main focus of research in semiconductor materials and devices [5][6][7] since the end of the 20th century. Due to the limitation of the GaN substrate, group III nitrides are generally grown by heteroepitaxy.…”

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

“…[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. The simulation result shows that at a current of 50 mA, the light output power of the DUV-LED with two parts linearly graded barrier MQWs has significant improvement as compared to stationary barriers.…”

“…[ 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; [ 23–25 ] 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 each barrier; [ 32 ] Y‐shaped barriers with alternate doped Si and Mg; [ 33 ] with step‐like QBs. [ 34 ] In addition, some scholars have also studied the influence of chip size on the optical and electrical properties of DUV‐LEDs.…”

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.…”