Résumé
Quaternary chalcogenide Cu2FeSnS4 (CFTS) thin layers have been grown by spray pyrolysis technique on glass substrates using different substrate temperatures (T-s = 160, 200, 240 and 280 degrees C). Physical properties of CFTS thin films were investigated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), spectrophotometer and Hall Effect. All results suggest that CFTS thin film synthesized at T-s = 240 degrees C has the best physical properties. XRD indicates an enhancement of crystalline quality of stannite CFTS elaborated at T-s = 240 degrees C with a maximum grain size about 45 nm and Raman spectroscopy confirms the purity phase of optimum sample. At T-s = 240 degrees C, atomic ratios of Cu/Fe/Sn/S were close to the theoretical ratios 2/1/1/4 and SEM images illustrates that the surface of the film is covered from a large number of micro-aggregates with spherical form. It is found that energy band gap and absorption coefficient values were about 1.46 eV and 9.8 10(4) cm(-1) respectively at T-s = 240 degrees C. Hall Effect measurements revealed that electrical resistivity of optimum sample decreased to 0.18 Omega cm. Thus, all experimental results demonstrate that CFTS thin film grown at T-s = 240 degrees C can be considered as a promising absorber material in solar cell devices. A higher photodegradation rate of MB was about 81% under sun light for 4 h which indicates that optimum CFTS thin film grown at T-s = 240 degrees C would be a cheaper alternative catalyst to replace TiO2 in photocatalysis applications.