Preparation and Charge Transfer at Sb2Se3/1L-MoS2 Heterojunction

Abstract

Owing to the strong optical absorption of Sb2Se3, building heterojunctions (HJs) by using thin-layer Sb2Se3 and other two-dimensional (2D) materials is critical to the design and applications of ultrathin optoelectronic devices. However, the preparation of HJs using Sb2Se3 and other transition metal dichalcogenide (TMDC) thin layers is still challenging. Herein, a chemical vapor deposition (CVD) method was used to prepare monolayer MoS2(1L-MoS2) and Sb2Se3 thin layers. A dry transfer method was subsequently used to build their HJs. Individual PL spectra and PL mapping results obtained at the HJs indicate a charge injection from 1L-MoS2 into Sb2Se3 flake, which was further confirmed by contact potential difference (CPD) results obtained by using Kelvin probe force microscopy (KPFM). Further measurements indicate a type-Ⅰ band alignment with a band offset finally determined to be 157 meV. The obtained results of Sb2Se3/1L-MoS2 HJs will benefit the rational design of novel ultrathin optoelectronic devices based on novel 2D absorber layers working in visible light.