Recent Progress in AlGaN-Based Deep-UV LEDs

Deep-ultraviolet (DUV) light-emitting diodes (LEDs) are in demand for a wide variety of potential applications, such as sterilization, water and air purification, medical uses, and so on. We have demonstrated 222-351 nm AlGaN and quaternary InAlGaN-based DUV-LEDs by developing a low threading dislocation density (TDD) AlN crystal. We achieved an external quantum efficiency (EQE) of about 4% and an output power greater than 30 mW in DUV-LEDs for use in sterilization applications by developing new crystal growth techniques.