Fabrication of Cu-2(ZnxMg1-x)SnS4 thin films by pulsed laser deposition technique for solar cell applications

In this study, the pulsed laser deposition technique was applied for the preparation and characterization of Cu-2(ZnxMg1-x)SnS4 (CZMTS) thin films for solar cell applications. The effects of various zinc/magnesium compositional ratios on the properties of the CZMTS thin films were investigated. The field emission scanning electron microscopy studies revealed that the CZMTS thin films exhibited dense, uniform and smooth surfaces. The X-ray diffraction studies on the as-deposited and annealed CZMTS thin films showed the prominent peak from the (112) plane for kesterite phase Cu2ZnSnS4. The Raman studies on the CZMTS thin films further confirmed formation of kesterite phase and beneficial MoS2 layer. Further, the Hall measurement studies on CZMTS thin films confirmed p-type electrical conductivity behavior. The conductivity increased from 2.31 S/cm to 7.98 S/cm with increased Mg concentration. The X-ray energy dispersive spectroscopy studies revealed formation of stoichiometric thin films. The direct optical band gap for the CZMTS thin films were found to be in the range of 1.3-1.5 eV, suggesting their potential application as a low cost and earth abundant thin film solar cell absorber material.