Electroluminescence from a Schottky-type p-GaN gate structure

Abstract

In this paper, we fabricate a Shcottky-type Ni/p-GaN/AlGaN/GaN device, and investigate its electroluminescence characteristics under the different forward bias voltages and at different temperatures. We find that when a forward gate bias is greater than 4 V, the electroluminescence comes from the p-GaN layer, indicating that electrons are injected from the channel into the p-GaN layer. While the forward gate bias is higher than 6 V, the GaN band edge emission emerges, indicating that the holes start to be injected into the channel region. As the temperature increases, the intensity of electroluminescence increases significantly, which reveals that the hole injection at the Ni/p-GaN interface is thermally enhanced. This work is essential for comprehensive understanding and improving the stability and reliability of the p-GaN gate power devices.