Cu2S/CuInoaGao(3)Se(2) (Cu2S/CIGS) core/shell nanowire arrays with epitaxial CIGS growth are synthesized by electrodepositing CIGS on Cu2S nanowire arrays. The electrodeposited CIGS is tetragonal CuIn0.7-Ga0.3Se2 with a band gap of 1.310 eV. The crystal structure of Cu2S is similar to that of CIGS. The interplanar distance of Cu2S ((2) over bar 04) is also similar to that of CIGS (112), so the CIGS shell grows epitaxially. Absorption measurements show that Cu2S/CIGS core/shell nanowire arrays exhibit higher light absorption than Cu2S nanowire arrays. Fabricating Cu2S/CIGS core/shell nanowire arrays with epitaxial CIGS growth shows promise for the preparation of single crystal CIGS one-dimensional nanostructures. (C) 2014 Elsevier B.V. All rights reserved.