222 nm single‐peaked deep‐UV LED with thin AlGaN quantum well layers

We fabricated 222 nm AlGaN multi‐quantum well (MQW) deep‐ultraviolet (DUV) light emitting diode (LED) on high quality AlN buffers grown by ammonia (NH3) pulse‐flow multilayer growth method on sapphire substrate. We obtained remarkable enhancement of emission intensity of 220 nm‐band DUV LED by introducing thin (<1.6 nm) quantum well. We realized a single peaked operation of a 222 nm DUV AlGaN MQW LED under pulsed current injection, which is the shortest wavelength of AlGaN LED on sapphire substrate. The maximum output power and external quantum efficiency of 222 nm AlGaN MQW LED were 14 μW and 0.003%, respectively. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)