Fabrication of a High-Quality Cu2ZnSn(S,Se)4 Absorber Layer via an Aqueous Solution Process and Application in Solar Cells

The development of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells determines the prospect of thin-film photovoltaic devices because of some of their strengths. However, the usual solution fabrication processes of CZTSSe absorbing layers are either too tedious or highly toxic. Here, we have developed an alternative strategy to prepare kesterite CZTSSe absorber films with a simple and low-toxicity solution process by replacing the commonly employed thiol-based compounds using the glycolic acid aqueous solution, which significantly reduces the environment pollution and toxicity, providing a possibility toward the green solvent process. The power conversion efficiency of 6.81% has been acquired based the aqueous solution-processed CZTSSe thin film via optimizing the fabrication technology.