Pseudomorphic AlxGa1-xN MQW based deep ultraviolet light emitting diodes over sapphire.

We report on the fabrication of AlGaN-based pseudomorphic light-emitting diodes over sapphire substrate with peak emission at 275 nm. A 0.6 µm thick n-AlGaN contact layer was grown using a novel pulsed silicon modulation doping technique, which enabled us to achieve a sheet resistance of ∼500Ω/□. In order to mitigate current crowding and Joule heating issues, we implemented the pixel-LED design with a total p-active area of 360 µm x 360 µm. Packaged devices exhibited light output powers of ∼7 mW at 100 mA dc pump current. The forward voltage was ∼ 8.8 V. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]