MOS-structured MoS2/GaN Schottky barrier diodes with high on/off current ratio and low threshold voltage

Abstract

GaN Schottky barrier diodes (SBDs) have been investigated for a variety of power applications. However, the problems of low on/off current ratio and high threshold voltage caused by the difficult high-quality doping restrict its utilization in power devices. In this work, quasi-vertical MoS2/GaN SBDs with Metal-Oxide-Semiconductor (MOS) structure have been proposed. The MOS structure is formed by the part of anode (Ni/Au) over the Al2O3, Al2O3, and monolayer MoS2. Monolayer MoS2 exhibits n-type doping and p-type doping under forward bias and reverse bias, respectively, which realizes an adjustment in the Fermi level of the monolayer MoS2, resulting in a change in the resistance of the SBDs. The as-prepared SBDs present a high on/off current ratio of 2.40 × 1011, a low threshold voltage of 0.55 V at 1 A/cm2, and a low reverse leakage current of 2.50 × 10−10 A/cm2 at −1 V. This work shows that the MOS-structured MoS2/GaN SBDs are promising for next-generation power electronics.