Efficient visible-light-driven water splitting performance of sulfidation-free, solution processed Cu2MgSnS4 thin films: Role of post-drying temperature

•We introduced a molecular ink based, sulfidation-free approach for fabrication of Cu2MgSnS4 thin films.•The photoelectrochemical performance of Cu2MgSnS4 was investigated for the first time.•Phase tunability form kesterite to stannite was observed with increase in post-drying temperature.