Low cost preparation of Cu2ZnSnS4 and Cu2ZnSn(SxSe1−x)4 from binary sulfide nanoparticles for solar cell application

A low-cost non-vacuum process for fabrication of Cu2ZnSnS4 (CZTS) and Cu2ZnSn(SxSe1−x)4 (CZTSSe) films by solvent-free mechanochemical method and doctor blade process is described. First, CuS, ZnS and SnS nanoparticles are synthesized via a facile, solvent-free route, which is low cost and easy to scale-up. Second, the sulfides nanoparticulates precursors are deposited in a thin layer by doctor blade technique. Finally, the dry layers are sintered into CZTS/CZTSSe thin films. Different annealing processes are used, and the influences of incorporation of sulfur/selenium on the CZTS/CZTSSe films have been investigated. These structure, morphology and optical properties of CZTS/CZTSSe films are suitable for thin film solar cell fabrication.