Two-dimensional metal dichalcogenide/monochalcogenide thin flakes have attracted much attention owing to their remarkable electronic and electrochemical properties; however, chemical instability limits their applications. Chemical vapor transport (CVT)-synthesized SnTiS₃ thin flakes exhibit misfit heterojunction structure and are highly stable in ambient conditions, offering a great opportunity to exploit the properties of two distinct constituent materials: semiconductor SnS and semi-metal TiS₂. We demonstrated that in addition to a metal-like electrical conductivity of 921 S/cm, the SnTiS₃ thin flakes exhibit a strong bandgap emission at 1.9 eV, owing to the weak van der Waals interaction within the misfit-layer stackings. Our work shows that the misfit heterojunction structure preserves the electronic properties and lattice vibrations of the individual constituent monolayers and thus holds the promise to bridge the bandgap and carrier mobility discrepancy between graphene and recently established 2D transition metal dichalcogenide materials. Moreover, we also present a way to identify the top layer of SnTiS₃ misfit compound layers and their related work function, which is essential for deployment of van der Waals misfit layers in future optoelectronic devices.

二维金属二硫化氢/单硫属金属薄片由于其卓越的电子和电化学性能而备受关注。但是，化学不稳定性限制了它们的应用。化学气相传输（CVT）合成的SnTiS ₃薄片表现出失配的异质结结构，并且在环境条件下高度稳定，为利用两种不同的构成材料的特性（半导体SnS和半金属TiS _2）提供了绝佳的机会。我们证明，除了金属样电导率为921 S / cm外，SnTiS ₃薄的薄片在1.9 eV处显示出很强的带隙发射，这是由于错配层堆叠中的范德华相互作用弱所致。我们的工作表明，错配异质结结构保留了各个组成单层的电子特性和晶格振动，因此有望弥合石墨烯与最近建立的2D过渡金属二硫化二氢材料之间的带隙和载流子迁移率差异。此外，我们还提出了一种识别SnTiS ₃错配化合物层及其相关功函数的方法，这对于在未来的光电器件中部署范德华错配层至关重要。