Impacts of the top antireflection films on the performance of blue micro-LEDs

In this work, we have fabricated the blue micro-light-emitting diodes (micro-LEDs) with 0, 8, 10 and 12 periods of SiO₂/TiO₂ anti-reflection (AR) films by using the technology of atomic layer deposition. In addition, by measuring the properties of these AR films and the optoelectronic performance of these micro-LEDs, the impacts of these AR films for these micro-LEDs have been analyzed. For the poorer thermal dissipation characteristics of SiO₂ and TiO₂ than that of air, there would be lower resistance in the micro-LEDs with more periods of AR films under high current injected condition. In addition, the optical properties of these AR films result in the higher external quantum efficiency in the micro-LEDs with more periods of AR films, and the light distribution of micro-LEDs with 0, 2, 4, 6, 8, 10, 12 and 14 periods of AR films has been analyzed by using the FDTD software. Moreover, the junction-temperature rise and the stability of these micro-LEDs has been investigated by using the 1000 h accelerating aging test under (85 °C/85% humidity) under the injection current of 40 mA, these results indicate that AR films have excellent reliability under 85 °C and 85% humidity conditions, and the deposition of AR films would result in the poorer thermal behavior in micro-LEDs. We hope these findings could give reference for the fabrication of high-performance micro-LEDs.