Preparation And Characterization Of Cu₂ZnSn（S,Se）₄Thin Films

Contemporarily, the demand of energy is largely fulfilled by the fossil fuels which are non-reproducible energy resource. Fossil fuel combustion, at the same time, causes the world’s population. Hence, Fundamental way to solve this problems is to exploit a candidate of fossil fuels which is cleaning、environmental and reproducible. In the midst of the varying reproducible energy sources, solar energy which is clean、abundant and long-term use turns into the best choice. CZTS which as a result of its excellent material properties, such as earth-abundant as well as very low toxic elements of Zn and Sn、high conversion efficiency、good radiation resistance and huge reserves, stands out from the crowd.In this work, a simple and pacific one-pot oleylamine solvothermal synthetic method was exploited to synthesize CZTS nanocrystals. And the Cu2ZnSn(S,Se)4(CZTSSe) thin films were prepared by selenizing CZTS nanocrystals. Results show that the single phase structural CZTS precursor powder with the stoichiometric ratio can be obtained under the condition of stable Ar pressure. The CZTSSe films have poor copper composition, and, with the temperature increasing, Se element content increased then leveled off while the content of S element began to decrease then gradually increase. The prepared CZTS nanocrystals have formed kesterite crystal structure and the CZTSSe films with kesterite crystal structure have also been obtained after annealing at500℃for20min. And the CZTSSe films exhibits a smooth, uniform and crack-free topography. Moreover, it shows strong optical absorption from visible to near IR region, its optical band gap (Eg) figure is found to be about1.44eV.