Kesterite monograins for solar cells and water splitting applications

Highlights: • Suitability of Kesterites for photoelectrochemical application. • The anion substitution effects for photovoltaic and water splitting applications. • Identification of band positions of Kesterite interfaces to aqueous solutions. • Too negative flatband potentials with respect to the redox potentials of water. • Very high overpotentials for Hydrogen evolution. Photoelectrochemical cells are at the forefront of promising methods of direct solar hydrogen production. It may become the best solution to produce storable chemical energy in a sustainable way and an alternative for combining photovoltaics with expensive storage systems like batteries. This environmentally friendly system based on an earth-abundant kesterite monograins with low processing cost and the outstanding semiconductor properties of single crystals, enables large-scale commercialization. This study aims to evaluate Cu₂ZnSn(S_xSe_1-x)₄ monograins with x = 0 to x = 1 for photovoltaic and photoelectrochemical water splitting applications.