Controlling the physicochemical and optoelectronic properties of novel quaternary chalcogenide CuSbSnS₃ using different sulphurizing agents
摘要
Copper Antimony Tin Sulphide (CuSbSnS₃, CATS) was successfully synthesized through both hydrothermal and solid-state reaction (SSR) methods using different sulfur precursors. XRD analysis confirmed that the material crystallized in an orthorhombic structure. The sulfur source significantly influenced particle size and morphology: thiourea (TU) produced well-defined nanocrystalline structures with flake-like particles around 60 nm and uniformly distributed nano-crystallites of 5–10 nm, while other precursors such as L-cystine, Na₂S, and elemental sulfur generated larger particles (150–250 nm). Optical analysis revealed suitable band gap values ranging from 1.25 to 1.70 eV with strong absorption in the visible–NIR region. Post-annealing treatments enhanced conductivity by reducing resistivity and limiting grain growth. Photoelectrochemical measurements further confirmed that TU-derived CATS exhibited superior charge transport properties, including the lowest charge-transfer resistance (50 Ω), highest electrical conductivity (9.41 × 10⁶ Ω⁻¹·cm⁻¹), enhanced carrier mobility (2.50 × 10⁵ cm²·V⁻¹·s⁻¹), and higher carrier concentration (2.35 × 10²⁰ cm⁻³). Consequently, the TU-synthesized CATS demonstrated the highest power conversion efficiency of 7.77%, underscoring its strong potential for advanced photoelectric and solar-energy applications.