Performance Improvement of Light-Emitting Diodes with W-Shaped InGaN/GaN Multiple Quantum Wells
Using APSYS simulation program, we investigate the optical performance of InGaN/GaN multiple quantum well (MQW) blue light-emitting diodes (LEDs) with a W-shaped well structure with respect to optical output power and internal quantum efficiency with variation in injection current. The concept of W-shaped quantum well is proposed to lower the polarization field and to obtain better overlapping between the peaks of electron and hole concentrations. Our proposed LED with W-shaped quantum wells exhibits 91% improvement in output power as compared to a rectangular quantum well LED. Furthermore, our proposed LED shows 20% efficiency drooping in contrast to 49% with a conventional LED at an input current = 120 mA. Moreover, we analyze our results with the help of band diagram, electron and hole concentrations, and also radiative recombination rate in the wells obtained from numerical simulation program.
KeywordsAPSYS simulation Efficiency droop LEDs W-shaped InGaN MQWs
The first author is thankful to UGC for supporting his fellowship vide no. F1-17.1/2013-14/RGNF-2013-14-SC-WES-52737/ (as may be seen in SA-III/Website).
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