Characterizations of sidewall recombination behaviors of AlGaInP red light-emitting diodes with micron-scale mesa size by steam oxidation

We report size and oxidation temperature-dependent performance optimization of sidewall steam oxidation for AlGaInP red micro-light-emitting diodes (µLEDs). Devices with mesa sizes from 100 × 100 μm² down to 5 × 5 μm² were fabricated. Our results reveal that steam oxidation significantly enhances light output and suppresses nonradiative recombination, with optimal oxidation time decreased with device size. At cryogenic temperatures, the best performance is achieved at even shorter oxidation times, highlighting the need for condition-specific processing. Through the ABC model, we show that sidewall oxidation reduces Shockley-Read-Hall recombination and enhances radiative efficiency, particularly in small devices. This study provides a practical guideline for optimizing sidewall treatment to improve the performance of AlGaInP µLEDs for high-resolution display applications.