Luminous efficiency of InGaN/GaN-based green micro-LED improved by n-side graded quantum wells

InGaN/GaN-based micro-light-emitting diodes (micro-LEDs) are considered as candidate technologies for the next generation display and visible light communication (VLC). In this study, we proposed an n-side graded indium content quantum well structure to improve the luminous efficiency and comprehensive performance of InGaN/GaN-based green micro-LED. The InGaN quantum wells with n-side graded indium content can improve the crystal quality, alleviate the quantum-confined Stark effect (QCSE), and improve the radiation recombination efficiency at low current. The experimental results demonstrate that the peak external quantum efficiency (EQE) of micro-LED with n-side graded indium content is improved by 10.4% compared to the micro-LED with traditional square quantum wells, and it has better color saturation. This work provides a feasible direction for the commercial production and application of high luminous efficiency green micro-LED.