One-step synthesis of metal/semiconductor heterostructure NbS₂/MoS₂

Chemical vapor deposition (CVD) has proven its surpassing advantages, such as larger scale, interlayer orientation control, and clean interface, in the synthesis of transitional metal dichalcogenide (TMDC) semiconductor/semiconductor van der Waals (vdW) heterostructures. However, it is suffering problems of high melting points and low chemical reactivity of metal oxide feedstocks in the preparation of high-quality metal/semiconductor (M/S) TMDC vdW heterostructures. Here, for the first time, we report the synthesis of the M/S TMDC vdW heterostructure NbS₂/MoS₂ via a one-step halide-assisted CVD method, which effectively overcomes the drawbacks of metal oxide precursors. This one-step method provides the high quality and clean interface of the NbS₂/MoS₂ heterostructure, which has been proved by the transmission electron microscopy characterization. A mechanism that MoS₂ finishes the growth first and subsequently serves as a superior substrate for the growth of NbS₂ is proposed. This novel method will open up new opportunities in the syntheses of other M/S TMDC vdW heterostructures and will facilitate the research of the TMDC M/S interface.