Synthesis of Cu 2 ZnSnSe 4 thin‐film solar cells from nanoparticles by a non‐vacuum mechanical ball milling and rapid thermal processing

A truly simple, reproducible, and environmentally friendly non-vacuum synthesis method for synthesising of carbon-free Cu2ZnSnSe4 (CZTSe) absorber layer has been presented. The stannite CZTSe nanoparticles with an average size of about 20 nm distributions were fabricated by an ambient mechanical milling procedure using Cu2Se, Zn, Sn, elemental selenium powders as raw materials and non-toxic ethanol as solvent. The compact CZTSe thin films were formed via an annealing treatment under Ar/Se atmosphere using rapid thermal processing. The optical properties of the obtained CZTSe thin films are the absorption coefficient (α) exceeding 104 cm−1 and E g of 0.91 eV. The electrical properties of the CZTSe thin films indicate p-type semiconductor behaviour. The photovoltaic properties of this solar cell are power conversion efficiency of 0.18%.