Development of UV light-emitting diodes based AlGaN/GaN heterojunction utilizing thermal oxidation annealing

Ultraviolet (UV) irradiation has a significant impact on enhancing the performance of sensors. Currently, there is still an urgent need for devices that are simple and easy to fabricate. In this work, a cost-effective and convenient method was employed to fabricate a UV light emitting diode. A four-inch silicon based AlGaN/GaN heterojunction substrate was used. The Ni/Au (20/20 nm) layer was deposited on the AlGaN barrier layer, followed by thermal oxidation to prepare the UV diode. The diode annealed in oxygen can emit UV light at a wavelength of 365 nm and is visible, and no light is emitted from the device in nitrogen annealing. The I–V and C–V characteristics of the device are tested to explore the mechanism. Transmission electron microscopy and technology computer aided design simulation methods were used to analyze the device luminescence mechanism.