OPTICAL CHARACTERIZATION OF TIN SELENIDE (SNSE) THIN FILMS PREPARED BY THERMAL EVAPORATION FROM ELEMENTAL PRECURSORS (SE) AND (SN)

Tin selenide (SnSe) thin films with a thickness of ) were prepared by direct thermal evaporation of a mixture of its elemental precursors, Selenium (Se) and Tin (Sn), in a 1:1 molar ratio on glass substrates at room temperature. X-ray diffraction (XRD) and morphological analysis (SEM/AFM) confirmed that the as-deposited sample possesses a pure orthorhombic crystalline phase, whereas stepwise thermal treatment led to phase decomposition and impurity formation. Optical analysis revealed a high absorption coefficient () and two bandgaps: a direct gap of 1.42 eV and an indirect gap of 0.65 eV. The experimental results demonstrate the viability of these films as efficient, low-cost active materials for solar cell and broadband photodetector applications.