Influence of annealing condition on the photovoltaic performance of Cu2ZnSnSe4 thin film solar cells

The synthesis of highly crystalline Cu₂ZnSnSe₄ (CZTSe) absorber films through two-stage process of the selenization of a sputtered metallic CZT precursor layers on Mo substrate followed by annealing under selenium vapor was a promising approach for fabricating high efficiency solar cells. In this study, CZTSe films have been characterized in detail using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), Raman spectroscopy, and solar simulator. It was found that the structural and optical properties of CZTSe films. The SEM and Raman scattering analysis showed the formation of the CZTSe compound and crystalline quality of the CZTSe can be controlled through varying by the heating rate. Increase of the heating rate can increase the grain size of CZTSe absorber films, and lead to effect the CZTSe compound. Solar cells with the Al/Ni/AZO/i-ZnO/CdS/CZTSe/Mo showed the conversion efficiency of 0.2 % to 1.78 % for 0.13 cm² with V_oc = 0.06 V to 0.21 V, J_sc = 11.65 mA/cm² to 31.81 mA/cm², and FF = 0.28 to 0.31.