ZnO/AlGaN Ultraviolet Light Emitting Diodes

We report on the optical and electrical properties of n-ZnO/p/-AlGaN heterojunctions. Ga doped n-type ZnO layers were grown using chemical vapor deposition on Mg doped p-type AlGaN epitaxial layers. AlGaN epitaxial layers with 12 at.% Al were grown on 6H-SiC by hydride vapor phase epitaxy. Rectifying diode-like behavior with a threshold voltage of 3.2 V was achieved. Intense ultraviolet electroluminescence peaking at a wavelength of 390 nm was observed at 300 and 500 K as a result of hole-injection from the n-ZnO layer into the p-AlGaN layer of the heterostructure.