Temperature-dependent interface barrier behavior in MoS2/n-GaN 2D/3D heterojunction

Abstract

We fabricated MoS2/n-type GaN 2D/3D heterojunction diode, investigated its structural properties and temperature-dependent current–voltage (I–V) characteristics. The MoS2 2D film on GaN is 5.2-nm-thick with ~ 0.64 nm interlayer distance. The Barrier height and ideality factor of the MoS2/n-type GaN heterojunction increase and decrease, respectively with rising temperature, associated with the barrier height inhomogeneities. The barrier height inhomogeneity evaluation considering the Gaussian distribution of barrier heights indicate the presence of double Gaussian barrier distribution with mean barrier heights of 0.95 and 1.44 eV and standard deviations of 0.11 and 0.18 eV in the temperature range of 125–225 and 225–400 K, respectively. Reverse current showed an electric field dependence with the carrier transport dominated by Poole-Frenkel emission irrespective of the temperature.