Investigating the Effects of AlGaN insertion Layers on Ultravoilet-C MicroLED Performance

This study investigates the optimization of optoelectronic characteristics of AlGaN-based Ultraviolet-C micro light-emitting diodes (μLEDs) in the 270-280 nm range. The research introduces two approaches: integrating AlGaN insertion layers (ILs) and graded AlGaN ILs within multi-quantum wells (MQWs). Due to the notable sidewall defects and high surface-to-volume ratio, μLEDs often suffer from dominant surface recombination effects. However, the strategic use of ILs in MQWs enhances carrier confinement within the quantum wells, thereby reducing sidewall defect trapping. Graded ILs further improve radiative recombination by retaining carriers more effectively in QWs. Results show a marked increase in internal quantum efficiency (IQE) from 35% to 55% and 63% with AlGaN ILs and graded AlGaN ILs. Additionally, emission intensity is enhanced fourfold with ILs and sixfold with graded ILs compared to the reference structure, demonstrating significant advancements in μLED performance.