Spatial distribution of current density and thermal resistance of high-power AlInGaN vertical and face-up light-emitting diodes

This paper presents a comprehensive analysis of the electroluminescence (EL) and current distributions in connection with heat transfer (thermal resistance) in high-power “vertical" and "face-up" AlGaInN light emitting diodes (LEDs). The study was carried out using a combination of high-resolution EL mapping techniques giving information on the lateral distributions of near-field light emission intensity and thermal transient measurements for evaluation of thermal resistance of LEDs and its elements. It was shown that poor current spreading at high current density causes increase in thermal resistance.