[15a-422-1~12] 3.13 Semiconductor optical devices

[15a-422-8] High-efficiency, High-power AlGaInP Thin-film LEDs with Small Truncated Cones as the Light-extraction Structure

〇Xue-Lun Wang¹, Naoto Kumagai¹, Guodong Hao¹ (1.AIST)

Keywords:AlGaInP, light emitting diode, light extraction efficiency

Small truncated cones with well-defined dimensions were fabricated on the light-extraction surface of high-power, high-efficiency thin film AlGaInP red LEDs. A maximum external quantum efficiency of 39.3% (after resin encapsulation) was observed from the fabricated device, which is an efficiency about 10% higher than that typically obtained from conventional high-power thin film AlGaInP LEDs with random roughness as the light extraction structure. It was found through FDTD simulation that the truncated cone structure seems to be more efficient for the extraction of high-angle light than the random roughness structure.