Determination of band offsets at GaN/single-layer MoS<inf>2</inf> heterojunction

Abstract

We report the band alignment parameters of the GaN/single-layer (SL) MoS heterostructure where the GaN thin layer is grown by molecular beam epitaxy on CVD deposited SL-MoS /c-sapphire. We confirm that the MoS is an SL by measuring the separation and position of room temperature micro-Raman E and A modes, absorbance, and micro-photoluminescence bandgap studies. This is in good agreement with HRTEM cross-sectional analysis. The determination of band offset parameters at the GaN/SL-MoS heterojunction is carried out by high-resolution X-ray photoelectron spectroscopy accompanying with electronic bandgap values of SL-MoS and GaN. The valence band and conduction band offset values are, respectively, measured to be 1.86 ± 0.08 and 0.56 ± 0.1 eV with type II band alignment. The determination of these unprecedented band offset parameters opens up a way to integrate 3D group III nitride materials with 2D transition metal dichalcogenide layers for designing and modeling of their heterojunction based electronic and photonic devices. 2 2 2 2g g 2 2 1 1