227 nm AlGaN Light-Emitting Diode with 0.15 mW Output Power Realized using a Thin Quantum Well and AlN Buffer with Reduced Threading Dislocation Density

Abstract

AlGaN multi-quantum-well (MQW) deep-ultraviolet (DUV) light-emitting diodes (LEDs) fabricated on sapphire substrates with emission at 227 nm are demonstrated. A remarkable enhancement in the DUV LED output power was achieved by using a thin AlGaN quantum well only 1.3 nm in thickness, with atomically flat hetero-interfaces, together with an AlN buffer layer of reduced threading dislocation density. The AlGaN-MQW DUV LEDs exhibited single emission peaks. The output power was 0.15 mW with injection current of 30 mA and the maximum external quantum efficiency was 0.2%, under room temperature pulsed operation.