Electrochemical underpotential codeposition of MnS thin films for photovoltaic applications

Manganese(II)sulfide (MnS) is a candidate component for a window or buffer material in solar cells; the ability to synthesize this compound by electrodeposition may open novel routes toward the low-cost, large-scale production of multicomponent chalcogenides with continuously tunable properties. We show here that underpotential codeposition enables formation of MnS films with precise stoichiometry and hexagonal structure. Film morphology consists of polycrystalline polygonal features. The films exhibit a bandgap of 3.9 eV, sometimes together with other, lower bandgaps due to secondary phases; these materials are also photoactive, with an observed photon-to-current conversion efficiency of ∼10%.