UV LEDs with Low Dislocation GaN Buffer Layers Grown by MOCVD

New MOCVD grown UV (ultra-violet) LEDs using low dislocation density GaN buffer layers on sapphire have been studied. Two different LED characteristics of GaN substrates, i.e. 5um-thick and 20um-thick buffer layers, on sapphire are compared with each other. The enhanced LED characteristics show ~29.5% reduction in current-voltage resistance, ~8.5% reduction in turn-on voltage and output power saturation at higher current. Better GaN buffer quality and heat dissipation due to the lower defect density are believed to the enhanced reason.