Tunable crystal structure of Cu2SnS3 deposited by spray pyrolysis and its impact on the chemistry and electronic structure

•CTS crystal structure can be tuned to tetragonal, orthorhombic or monoclinic.•Proposed mechanism for solvation of metal chloride precursors in an aprotic media.•Unambiguous determination of the crystal structure by using Raman and XRD.•Valence and conduction band structure analysis by XPS-IPES.•Cu1+ and Sn4+ oxidation states determination using XPS and the Auger parameter.