Vertical conducting ultraviolet light-emitting diodes based on p-ZnO:As/n-GaN/n-SiC heterostructure

Vertical conducting light-emitting diodes based on p-ZnO/n-GaN structure were fabricated on conductive n-SiC(6H) substrates. The p-ZnO:As films were prepared by arsenic out-diffusion from a sandwiched GaAs interlayer on a GaN/SiC template, and the AsZn-2VZn complex was considered to be the most probable defect contributing to the p-type conductivity of the ZnO:As films. Under forward bias, an intense ultraviolet emission at ∼384 nm from the ZnO side was observed. The electroluminescence performance of the diode was remarkable in terms of its low emission onset and high-purity ultraviolet emission. Additionally, the unencapsulated diode showed good stability over a duration of 2 months.