Improving AlGaInP Micro-LEDs Characteristics via Varied Dielectric Passivation Layers

This study aims to improve the characteristics of AlGaInP-based micro light-emitting diodes (micro-LEDs) by utilizing three different passivation layers, including silicon dioxide (SiO2), distributed Bragg reflector (DBR), and aluminum oxide (Al2O3) grown by atomic layer deposition (ALD) in combination with DBR. In terms of transmittance and refractive indices, our proposed structure, constructed with ALD-grown Al2O3 and a nine-layered DBR, exhibits significant improvements in all aspects compared to the traditional structure with a 3000Å SiO2 passivation layer. Additionally, the structure demonstrates a 124.28% increase in external quantum efficiency (EQE) compared to the LED constructed with a nine-layered DBR. This result indicates that the ALD growth of Al2O3 effectively reduces sidewall losses, significantly impacting the improvement of micro-LEDs.