High-power UV InGaN/AlGaN double-heterostructure LEDs

Ultraviolet (UV) InGaN/AlGaN double-heterostructure (DH) light-emitting diodes (LEDs) with an external quantum efficiency of 7.5%, an output power of 5 mW and an emission wavelength of 371 nm were developed. High-power UV LEDs are obtained using an InGaN active layer with a thickness of 400 A instead of a GaN active layer. The localized energy states caused by In composition fluctuation in the InGaN active layer are related to the high efficiency of the InGaN-based LEDs.