Effect of sulfur content on improving physical properties of new sprayed Cu 2 MgSnS 4 thin films compound for optoelectronic applications

In this paper, chalcogenide Copper Magnesium Tin Sulfide Cu 2 MgSnS 4 (CMTS) thin films were deposited by chemical spray pyrolysis technique on glass substrates for different sulfur concentrations [S] = 35, 37, 40, 42, 45 and 50.10 −3 mol/l using double distilled water as solvent. During this study, structural, optical and morphological properties of CMTS thin films have been investigated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV–visible spectroscopy and fluorescence spectroscopy. XRD results have shown that CMTS thin films crystallize into the Kesterite phase with (112) reticular plane as preferred orientation for all sulfur concentrations but with the presence of some secondary phases. Grain size values of CMTS thin films have been varied depending on [S] values. Raman Spectra have been used to identify and confirm our CMTS material with the main characteristic peaks at 287 and 331 cm −1 have been found. SEM micrographs have shown different textures of surface morphology depending on [S] with a local presence of nanospheres at high [S]. Absorbance of CMTS thin films has reached value near to 95% for all [S] contents with an absorption coefficient in the order of 10 4 cm −1 in the visible range. The photocatalytic activity of CMTS thin films has been measured by photodegradation of EOSIN-Y (EY) organic dye. A high degradation rate, close to 98%, was found after 4 h of sunlight irradiation. All these experimental results show that sprayed CMTS thin films grown at [S] = 40.10 −3 mol/l can be considered as a powerful absorber candidate for solar cells and a performing catalyst to release EY organic dye.