Fabrication and characterization of n-ZnO/p-AlGaN heterojunction light-emitting diodes on 6H-SiC substrates

Abstract
We report on the fabrication of n- ZnO /p- AlGaN heterojunctionlight-emitting diodes on 6H-SiC substrates. Hydride vapor phase epitaxy was used to growp-type AlGaN, while chemical vapor deposition was used to produce the n-type ZnO layers. Diode-like, rectifying I–V characteristics, with threshold voltage ∼3.2 V and low reverse leakage current ∼10 −7 A , are observed at room temperature. Intense ultraviolet emission with a peak wavelength near 389 nm is observed when the diode is forward biased; this emission is found to be stable at temperatures up to 500 K and shown to originate from recombination within the ZnO.