Fabrication of a Cu2ZnSn(S,Se)4 photovoltaic device by a low-toxicity ethanol solution process.

Homogeneous molecular precursor solutions are excellent choices for obtaining smooth absorber layers, and they offer the potential to significantly lower the manufacturing cost of solar cells. Here, we present a thermally degradable metal butyldithiocarbamate-based solution approach to fabricate Cu2ZnSn(S,Se)4 solar cells. Low-cost Cu2O, ZnO, and SnO were used as the starting materials and were dissolved in the ethanol solution of butyldithiocarbamic acid. By tuning the composition of the Cu2ZnSn(S,Se)4 thin film, a power conversion efficiency of 6.03% on the basis of the active area has been achieved.