High-efficiency 269 nm emission deep ultraviolet light-emitting diodes

We report on 269 nm emission deep ultraviolet light-emitting diodes (LEDs) over sapphire. The material quality, device design, and contact processing sequence yielded devices with external quantum efficiencies as high as 0.4% for a pumped pulse current of 200 mA and 0.32% for a dc pump current of 10 mA. For a module of two LEDs connected in series, a record continuous-wave power of 0.85 mW (at 40 mA) and a wall plug efficiency of 0.16% (at 10 mA dc) were measured. (C) 2004 American Institute of Physics.