Controllable growth of nonlayered 2D MnS nanosheets with thickness-tunable semiconductor to metal transition

Abstract Two-dimensional (2D) materials have attracted great research interest owing to their remarkable properties and promising application in electronic and optoelectronic devices. However, modulating the electrical conduction feature of 2D materials to match the basic requirements for constructing various functional devices is still a big challenge. Herein, we report the conduction feature modulation and device application of nonlayered 2D MnS nanosheets synthesized via chemical vapor deposition (CVD). By precisely tuning the growth temperature from 500 to 710 °C, the thickness of MnS nanosheets can be continuously modulated from ~3.5 to ~118.8 nm with the grain size changing from ~5 to ~27 μ m. The as-grown MnS nanosheets possess uniform triangle morphology with high crystallinity and strong second-order nonlinear optical properties. Field-effect transistors based on MnS nanosheets exhibit an interesting conduction feature transition from p-type semiconductor to metal as the thickness increasing from thinner to thick. As results, the photodetector based on thinner MnS semiconductor achieves superior photoresponsivity of 20.47 A/W, high detectivity of 5.31 × 10 10 Jones, and relative fast response time of 180 ms. Our findings not only enrich the family of intrinsic p-type 2D materials but also open a new avenue for electrical property engineering in non-layered 2D materials.