Enhanced electronic and photoelectrical properties of two-dimensional Zn-doped SnS₂

Alloy engineering, with its ability to tune the electronic band structure, is regarded as an effective method for adjusting the electronic and optoelectronic properties of two-dimensional (2D) semiconductors. However, synthesizing metal-site substitution alloys remains challenging due to the low reactivity of metal precursors and the tendency for spatial phase separation during high-temperature growth. Here, we report the preparation of a high-quality metal-site substitution alloy, Zn_0.167Sn_0.833S₂, via the chemical vapor transport method, which exhibits excellent photoresponsivity and enhanced electrical transport properties. Comprehensive characterization techniques, including Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), and electron microscopy, unambiguously confirm the uniform Zn substitution in the as-prepared Zn_0.167Sn_0.833S₂ alloy. Furthermore, the photodetector based on the Zn_0.167Sn_0.833S₂ alloy demonstrated a high on/off ratio of 51 under white light, a wide spectral response range from 350 nm to 900 nm, and a broad dynamic power range of 80 dB under 638-nm illumination. In terms of transport properties, field-effect transistors (FETs) based on Zn_0.167Sn_0.833S₂ achieved a carrier mobility of 6.5 cm²⋅V⁻¹⋅s⁻¹, which is six times higher than that of SnS₂. This alloy semiconductor showcases significantly enhanced electronic and optoelectronic properties, offering great potential for the development of high-resolution photodetection technologies.