Core@shell and lateral heterostructures composed of SnS and NbS2

Abstract

The spatial arrangement of heterostructures based on two-dimensional layered materials is important in controlling their electronic and optoelectronic properties. In this contribution, by controlling the reaction kinetics and thus the nucleation and growth sequence of p-type SnS and metallic NbS₂, controllable preparation of both SnS@NbS₂ core@shell and SnS/NbS₂ lateral heterostructures was realized. The SnS@NbS₂ core@shell heterostructures were further applied in photodetectors, and interestingly, a negative photoresponse was observed due to the Seebeck effect exerted on the NbS₂ shell. Compared with the pure metallic NbS₂, the SnS@NbS₂ core@shell heterostructures showed a 15 times increased signal-to-noise ratio and much improved photocurrent stability, largely due to the charge and heat transfer between the SnS core and NbS₂ shell.