Temperature-dependent structural and optical properties of SnS films

The structural and optical properties of SnS films deposited on glass substrates have been studied at different temperatures under a vacuum of ${10}^{-6}\text{Torr}$ . At room temperature, the SnS films showed orthorhombic crystal structure with lattice parameters of $a=0.424$ , $b=1.107$ , and $c=0.3974\text{nm}$ . These films also showed an optical band gap of $\sim 1.47\text{eV}$ with a high absorption coefficient, $\sim {10}^5{\text{cm}}^{-1}$ . X-ray diffraction studies at different temperatures $\left(100-598\text{K}\right)$ demonstrated that the structure of the SnS films remains constant. However, the volume of the unit cell of SnS films increased with the increase of temperature. It might be due to the expansion of the lattice. The effect of temperature $\left(4-303\text{K}\right)$ on the band gap of SnS films is also marginal $\left(\sim 0.03\text{eV}\right)$ . It indicates that the SnS films are optically stable even at very low temperatures due to its stabilized structure. Therefore, SnS films offer an opportunity to be used as alternative semiconducting materials as active layers for the fabrication of optoelectronic devices.