AlGaInP-based Micro-LED array with enhanced optoelectrical properties

The micro lighting-emitting diode (Micro-LED) array devices have attracted attention due to increasing demand in augmented reality (AR), virtual reality (VR), LIFI light source, and other micro-display applications. However, with the decrease of micro-LED diameter, the performance of micro-LED is severely limited due to the size effect. In the work, the AlGaInP based red micro-LED with diameter ranging from 2 to 16 mu m was prepared to study the size effect of micro-LED array, the array with larger micro-LED diameter show higher external quantum efficiency (EQE), meanwhile, the carrier lifetime decrease with the decreasing of the diameter, which can be explained by more surface states in the micro-LED with smaller diameter. The enhancement of EQE by 2 times has been achieved after surface passivation in (NH4)2Sx solution.

Automated summary

The research finds that the larger the diameter of micro-LED, the higher the external quantum efficiency (EQE); as the diameter decreases, the carrier lifetime reduces, possibly due to more surface states present in the smaller diameter micro-LEDs.