An electrodeposition-annealing route to films of the promising p-type absorber material Cu2ZnSnS4 (CZTS) using layered metal precursors is studied. The dependence of device performance on composition is investigated, and it is shown that a considerable Cu-deficiency is desirable to produce effective material, as measured by photoelectrochemical measurements employing the Eu3+/2+ redox couple. The differing effects of using elemental sulphur and H2S as sulphur sources during annealing are also studied, and it is demonstrated that H2S annealing results in films with improved crystallinity. (C) 2008 Elsevier B.V. All rights reserved.