Structural and optical properties of thermally evaporated BiSb_2S_3 thin films

摘要

Thin films of BiSb_2S_3 with different thickness were deposited on glass substrate by vacuum thermal evaporation method and annealed at different temperatures. The elemental compositions of the films were confirmed by energy dispersive X-ray analysis (EDAX). The prepared films were structurally and morphologically characterized by X-ray diffraction (XRD) and microscopic (SEM & AFM) techniques respectively. It has been confirmed that the films possess polycrystalline nature with orthorhombic phase and the grain size of the films vary from 27.92 to 81.37 nm. The observed bandgap energies (varying from 1.787eV to 1.963 eV) of the films and its temperature dependence were estimated from optical absorption measurements.