Effect of deposition time on the physicochemical properties of co-electrodeposited Cu2SnS3 thin films for photovoltaic applications

This study highlights our optimization of the co-electrodeposition duration of Cu, Sn, and S on the titanium substrate in order to further improve the properties of Cu2SnS3 thin films in photovoltaic applications. After cyclic voltammetry identifying the potential for simultaneous Cu, Sn and S deposit, "Cu-Sn-S" layers were electrodeposited for deposition durations ranging from 10→20min. Structurally, X-ray-diffraction and Raman-spectroscopy have confirmed the formation of the single Cu2SnS3-phase, crystallizing in the triclinic system after 20min of electrodeposition. For this duration, the morphological SEM-EDX profile revealed a highly uniform distribution of grains with very optimal sizes for solar cell applications. To reinforce these conclusions, an optical analysis was carried out in the visible wavelength range, highlighting a strong absorption of the developed sample. In addition, the optical gap estimate, indicates that Cu2SnS3 exihibts a direct transition with a bandgap varying from 1.22 to 1.49eV when the deposition time is increased from 10→20min.