Influence of precursor thiourea contents on the properties of spray deposited Cu2FeSnS4 thin films

Semiconducting Cu2FeSnS4 (CFTS) thin films were spray-deposited with different thiourea contents in the precursor solution. The influence of thiourea contents (10-14 ml) in the precursor solution on the crystallographic, morphological, compositional, optical, electrical and thermoelectrical properties of CFTS films was studied. X-ray diffraction analysis confirmed stannite phase having tetragonal crystal structure. The surface of CFTS thin films had hexagonal crystals. Nearly stoichiometric deposition has been witnessed through energy dispersive X-ray spectroscopy. Optical bandgap was found to be in the range 1.54-1.76 eV based on the different thiourea contents in the precursor solution. The considerable reduction in electrical resistivity has been observed for TH13 sample. The CFTS thin films are p-type as confirmed from thermoelectrical analysis.