| Cu2ZnSnSe4thin film is a direct band gap of the p-type semiconductor material, which the room temperature band gap reaches to1.4～1.5eV and optical absorption coefficient reaches to104cm-1. It can be used in thin film solar cells as the absorbtion layer because of good optical and electrical properties.In this paper the Cu2ZnSnSe4thin film solar cells have been researched in theoretical analysis, structural design, materials research and preparation.DC magnetron sputtering prepares back contact layer, we adopt the pressure sputtering double-layer Mo film. By this way Mo film meets the requirement as back contact layer not only has good adhesion with the glass substrate but also low resistivity.By chemical bath deposition prepares CdS thin film, we deposite uniform and dense CdS film which adaptes as buffer layer in Cu2ZnSnSe4thin film cells by optimizing the process parameters of the water bath temperature, solution concentration, deposition time and so on.We prepare Cu2ZnSnSe4thin film by co-electroplating method to prepare Cu-Zn-Sn precursor and annealing in selenium vapors. The process parameters of the electrolyte concentration, deposition potential, the annealing time and annealing temperature influence on the surface of morphology, phase composition, chemical composition and the selenium reaction mechanisms, major findings are as follows:(1) We research technology of Cu-Zn-Sn precursors by co-electroplating method, optimize the electrodeposition process parameters. When the electrolyte concentration is19mmol/LCuSO4,70mmol/LZnSO4,10mmol/LSnCl4and500mmol/L sodium citrate, selenium source temperature keeps300℃and the substrate temperature is up to550℃, we prepare pure and in accordance with the stoichiometric ratio of Cu2ZnSnSe4thin film with p-type stannite structure.(2) To research the reaction mechanism of the Cu2ZnSnSe4thin film, we anneale Cu-Zn-Sn precursors in different substrate temperatures, preliminarily identified the reaction process of the Cu2ZnSnSe4thin film. |
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