Effect of the Quantum-Well Shape on the Performance of InGaN-Based Light-Emitting Diodes Emitting in the 400-500-nm Range

The electrical and optical properties of InGaN-GaN light-emitting diodes (LEDs) emitting in the 400-500-nm range and having a v-shaped quantum well (VSQW) and a u-shaped quantum well (USQW) are numerically investigated using APSYS simulation program. The simulation results showed that the devices containing VSQW have superior performance in terms of optical power and internal quantum efficiency droop compared to those with USQW. The optical power of the LEDs containing USQW increases gradually and reaches a maximum at 460 nm; however, the optical power of the LEDs with VSQW improves gradually, and the maximum is obtained in a window from 420 to 436 nm as a result of radiative recombination enhancement. The simulation results suggest that the higher performance of the VSQW is due to piezoelectric field reduction and an enhancement of electron and hole wave functions overlap.