To reduce the formation of the impurity phase, a buffer volume can be used to expands and smooths the surface of Cu2ZnSnS4(CZTS) thin film. In this study, a Cu-Zn-Sn-O(CZTO) precursor was synthesized through the process of coprecipitation-calcination-ball milling-spin coating. The influence of pH, temperature, and PVP on the constituent of hydroxides was investigated in the process of coprecipitation. Cu-Zn-Sn-O with appropriate compositions could be obtained by regulating the temperature and preservation time of the calcination stage. After ball milling to form a nano ink, and then spin coating, SEM images proved the generation of CZTO precursors, which effectively promoted the formation of Cu2ZnSnS4 thin films. Finally, the phase, microstructure, chemical composition, and optical properties of the Cu2ZnSnS4 thin films prepared by sulfurized annealing CZTO precursors were characterized by EDX, XRD, Raman, FESEM, Hall effect, and UV methods. The prepared CZTS thin film demonstrated a band gap of 1.30 eV, which was suitable for improving the performance of CZTS thin film solar cells.
Near-optimal composition of CZTS thin film via exploration of copper and thiourea molar concentration in spray pyrolysis technique
