Uniform monolayer Cu2ZnSn(S,Se)4 film based on novel precursor solution

Abstract

In this paper, we reported a novel precursor solution for the preparation of Cu2ZnSn(S,Se)4 (CZTSSe) film. Large-grain monolayer CZTSSe film can be obtained by using the precursor solution. The influence of selenization temperature on the properties of CZTSSe films and solar cells were investigated. We found the monolayer CZTSSe film can be prepared with the selenization temperature as low as 510 °C. While an increased selenization temperature was used, the size of the crystalline grains in CZTSSe film increased significantly, but the decomposition of CZTSSe material got more serious. As the increase of the selenization temperature, increased short-circuit current (JSC) can be achieved for the fabricated solar cell, which could be caused by the improved crystallinity of CZTSSe layer and the enlarged depletion width of solar cell (as much as 391 nm). On the other hand, the open-circuit voltage (VOC) decreased as the increase of selenization temperature, which may relate with the decomposition of CZTSSe material. The best solar cell achieved the efficiency of 11.4% (active area), which was based on CZTSSe film with the selenization temperature of 510 °C.