Structural, morphological and optical properties of Cu2SnS3 thin film synthesized by spin coating technique

In this paper, Cu2SnS3 film with about 600 nm thickness was successfully prepared, for the first time, by one step sol-gel spin coating route on glass substrate. The sample was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-vis spectroscopy. The X-ray diffraction result showed that the obtained layer was composed by Cu2SnS3 phase and has a tetragonal (I-42m) structure with (112) preferential orientation. The grain size calculated with Scherrer's formula was about 5 nm. The AFM and SEM studies reveal that the synthesized film is rough and compact without any visible cracks or pores. The film has high absorbance in the visible range (α > 5104 cm−1 at 2.88 eV) and direct band gap energy of 1.34 eV. This makes the material as a good candidate for low cost and friendly environment thin film solar cells.