Solid-State Synthesis and Optoelectronic Properties of Large-Sized SnS2 Single Crystal

Abstract

Two-dimensional layered metal dichalcogenide SnS₂ has garnered significant attention due to its outstanding electronic and optoelectronic properties, while large-sized SnS₂ single crystals are essential for the successful preparation of such high-performance SnS₂-based devices. Currently, chemical vapor transport (CVT) is the mainstream technique for growing SnS₂ single crystals, but it heavily relies on transport agents. Moreover, the residual of these agents may introduce additional point defects, which could degrade crystal purity and the optoelectronic properties of the resulting material. In this work, a simple solid-state method was adopted to grow high-quality SnS₂ single crystals without transport agents. X-ray diffraction (XRD) confirms that the crystal grows along the ($001$) plane. The Raman spectrum of the SnS₂ single crystal exhibits a characteristic peak at 313 $c{m}^{-1}$, indicating that the crystal has a 2H-SnS₂ configuration. The band gap of 2.12 $\mathrm{eV}$ was determined, and a single photoluminescence (PL) emission peak centred at 567 $\mathrm{nm}$, with an average PL lifetime of 3.73 $\mathrm{ns}$ was observed. Photoelectric measurements verify that the SnS₂ single crystal possesses fast and stable response curves, with a response time (${\tau }_r$) of 47 $\mathrm{ms}$ and a recovery time (${\tau }_f$) of 121 $\mathrm{ms}$.