Structural, electrical, and optical properties of as-grown and heat treated ultra-thin SnS films

摘要

The composition, structural, electrical, and optical properties of as-grown and heat treated tin-mono-sulfide (SnS) ultra-thin films have been studied. The ultra-thin SnS films were prepared on glass substrates by thermal resistive evaporation technique. A11 the SnS films contained nanocrystallites and exhibited p-type conductivity with a low Hall-mobility, <50 cm~2/Vs. All these films are highly tin rich in nature and exhibited orthorhombic crystal structure. As compared to other films, the SnS films annealed at 300 ℃ showed a low electrical resistivity of -36 ficm with an optical band gap of -1.98 eV. The observed electrical and optical properties of a1l the films are discussed based on their composition and structural parameters. These nanocrystalline ultra-thin SnS films could be expected as a buffer layer for the development of tandem solar cell devices due to their low-resistivity and high absorbability with an optimum band gap.