Research Of CZTSSe Thin Film On Flexible Substrates

Copper zinc tin sulfide(Cu2Zn Sn S4) semiconductor materials has emerge as one of the most promising thin film materials owing to its abundant elements, low cost, environmental benign, high absorption coefficient, adjustable band gap and high conversion efficiency. In this dissertation, we use thermal evaporation method, fabricate CZTSSe thin films on flexible substrates by different methods, and the morphology, crystal structure of the films were compared and analyzed, concluding that the most optimum preparation process for CZTSSe thin film. Then we explore the best growth condition of CZTSSe thin film, finally we fabricate CZTSSe thin film based on this growth condition which is suitable for the application of CZTSSe thin film solar cell. The main results are shown as follows:(1) Research the deposition method of CZTSSe thin films on flexible substrate. We deposit CZTSSe thin films by one-step method in low substrate temperature, two-step deposition method and two-step method in high substrate temperature, the morphology and crystal structures of the three kinds of technological conditions of preparation are contrasted and analyzed. Ultimately conclude that two-step method in high substrate temperature is the most optimal deposition method.(2) Research the optimal evaporation temperature of Cu evaporation source and Zn S evaporation source. We deposit thin films by two step method in high substrate temperature, the evaporation temperature of the Cu source and Zn S source are changed, analysis, through the analysis of the morphology and crystal structure of films in different evaporation temperature, finally conclude that the optimal evaporation temperature of Cu source is 1160℃, the optimal evaporation temperature of Zn S source is 730℃.(3) Through the improvement of process, we fabricate CZTSSe thin film which is suitable for device applications. The morphology and the crystal structure of the films have been analyzed, the Raman spectra of the films and single-phase compounds have been compared, we don’t find the other two phase and three phase.