Search

Kesterite compound Cu2ZnSnS4 is the most promising next leader in the chalcogenide thin films technology as it is based on earth-abundant elements. In this work, kesterite thin films were prepared with a wet chemistry method by using a DMSO solution containing thiourea and acetylacetone, without further addition of vapour sulfur compounds to obtain the Cu2ZnSnS4 phase. The composition and stability of the molecular precursor-ink were investigated by EPR, IR and Raman spectroscopy. Acetate precursors were proved to have a primary role in creating a network in the sol-gel transition by bridging the metals in solution, together with thiourea and DMSO coordination. The high-quality of the thin films, obtained by spin coating deposition and thermal treatment at 500°C, was assessed by XRD, Raman, Energy-Dispersive spectroscopy and optical analysis, which revealed a direct band gap of 1.5 eV. Therefore, the precursor-ink and the deposition process developed in this work are very well suitable for solar cell application.