Synthesis, structure, optics and electrical properties of Cu2FeSnS4 thin film by sputtering metallic precursor combined with rapid thermal annealing sulfurization process

Abstract Cu2FeSnS4 (CFTS) thin film has been synthesized by rapid thermal annealing sulfurization of radio-frequency magnetron sputtered precursor. X-ray diffraction pattern indicates that all phases belong to CFTS with tetragonal structure. The strain which exists in the film is calculated to be 8.29×10−3 using the Williamson–Hall method. Raman spectrum and infrared reflectivity present two A1, two B and three E optical vibration modes. The band gap of CFTS is evaluated to be 1.42 eV by the transmission spectrum. The electrical properties of CFTS with the structure of glass/Mo/CFTS/CdS/i-ZnO/AZO have also been discussed. The open circuit voltage (Voc) is 110 mV, short circuit density (Jsc) is 2.5 mA cm−2 and fill factor (FF) is 26.3%. These results are helpful to the preparation and further study of CFTS thin films for the solar cell application.