Band alignment of MoS2/SiC heterojunctions with ultrahigh rectifying ratio and photovoltaic effect

Abstract

Wide-bandgap semiconductor SiC's superior properties can be tailored by atomically thin MoS2 through its optoelectronic characteristics, driving innovation in next-gen optoelectronic and power devices. However, the MoS2/SiC interaction mechanism remains unclear, particularly concerning their structures, properties, and application potential. Here, we prepared large-area MoS2 films on 4H-SiC, and the structure and monolayer uniformity were determined by surface morphology phase characterization. Band structure analysis and theoretical calculations reveal that the MoS2/SiC heterojunction adopts a type-II band alignment, with a valence band offset (ΔEV) of up to 1.89 eV, resulting in a rectification ratio of up to 5.83 × 107. Notably, this heterostructure shows a pronounced photovoltaic response in both UV and visible ranges that differs from other studies, with fill factors values of ∼0.28 (340 nm) and ∼0.33 (532 nm). These results demonstrate the potential for scalable fabrication of high-performance mixed-dimensional heterojunctions, highlighting their promise for optoelectronic and power device applications.