The Electrochemical Properties Study Of Cu₂XSnS₄ （X=Zn,Co,Ni,Fe）Films Counter Electrode

Solar cells is a kind of device that can converse light to energy. In recent years, the dye sensitized solar cells （abbreviations:DSSCs） and quantum dot sensitized solar cells （abbreviations:QDSSCs） receive more attention, mainly due to their simple preparation process, low cost and a relatively high photoelectric conversion efficiency. The commonly used counter electrode material in DSSCs is Pt, owing to its high electaical conductivity, superior electrocatalytic activity and good stability. However, the large-scale manufacturing of DSSCs with Pt counter electrode may be limited because of its low abundance and high cost. Therefore, it is very important to develop the new low-cost and Pt-free counter electrode materials with a relatively high conversion efficiency for DSSCs. The elements of copper zinc tin sulfur（Cu₂ZnSnS₄/CZTS） have rich reserves on the earth and are of low cost, the CZTS has become the most promising counter electrode material for DSSCs. Based on some research, we have found that the CZTS is not only suitable for DSSCs, and also can be applied to QDSSCs.In this work, we synthesized a series of CXTS （X=Zn, Co, Ni, Fe） materials and systematically compared their performances with that of the traditional Pt-based counter electrode for the reduction of iodine(I^-/I^3-), copper(Co（dbbip）₂^2+/3+), ferric(Fe（CN）₆^4-/3-) and polysulfide(S^2-/Sn^2-) redox couples, respectively. The Tafel-polarization measurements indicated that these CXTS materials present comparable electrocatalytic activities as Pt-based catalysts in iodine and ferric electrolytes. But in the copper and polysulfide electrolytes, these materials showed better electrocatalytic activities than Pt-based material. The measured cell efficiencies of the CXTS-CE and Pt-CE cosensitized solar cells are about 4.1%. The universality of CXTS series in different electrolytes shows their potential application as the alternative counter electrodes in dye-sensitized solar cells and quantum dot-sensitized solar cells. According to the experiment, we found that in different electrolytes, CXTS can be used as the counter electrode of sensitized solar cells, this means that CXTS film can be used as a...