Layers of the binary compound InSb, with thicknesses in the micron range, were electrodeposited from a sodium citrate-citric acid solution onto polycrystalline Cu substrates and onto single crystal Si. The stoichiometry of the layers was found to depend primarily on the ratio of InCl3 to SbCl3 in the electrolyte, and less sensitively on applied potential and pH, within wide ranges of these parameters. Post-deposition crystallite grain growth and phase separation into zincblende InSb and excess metals were observed. Intraband absorption coefficients were low for near- stoichiometric deposits. Near-stoichiometric deposition onto single crystal Si yielded larger crystallites than did deposition onto polycrystalline Cu or non-stoichiometric deposition onto single crystal Si. These results should encourage efforts to achieve device quality InSb by electrodeposition for photonic crystal, nanostructure and nanodevice applications. (C) 2003 Elsevier B.V. All rights reserved.