Angular color variation in micron-scale light-emitting diode arrays

Abstract

A simulation scheme was developed to explore the light distribution of full-color micron-scale light-emitting diode (LED) arrays. The influences of substrate thickness, patterning, and cutting angle of the substrate on several important features, such as light field pattern, light extraction efficiency, and color variation, were evaluated numerically. An experiment was conducted; the results were consistent with simulation results for a 225 x 125 mu m(2) miniLED and those for an 80 x 80 mu m(2) microLED. Based on the simulation results, the light extraction efficiency of LED devices with a substrate increases by 67.75% over the extraction efficiency of those without a substrate. The light extraction efficiency of LED devices with a substrate increases by 113.55% when an additional patterned design is used on green and blue chips. The calculated large angle Delta u'v' can be as low as 0.015 for miniLED devices. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement