This study describes a method for the fabrication of an electrochemical atomic layer deposition (EC-ALD) used to fabricate the ternary, semiconducting compound, CuInSe2 (CISe), onto a flexible, carboxyl-functionalized multi-walled carbon nanotube/polyimide (COOH-MWCNT/PI) nanocomposite membrane. The elements were deposited using amperometric methods (I-t) in the following sequence: Se/Cu/Se/In/Se/Cu/Se/In and so on. in which the optimum deposition potential for each element was obtained via a cyclic voltammetry (CV) technique. Field emission scanning electron microscopy (FE-SEM) showed that the deposits consisted of many spherical nanoparticles, and energy dispersive spectroscopy (EDS) analysis indicated that the atomic ratio of the deposits (CuInSe) was 1.14 1.00 2.18, similar to the stoichiometric value of the compound. Near Fourier transform infrared spectroscopy (FT-IR) transmission measurements provided a band gap of 1.05 eV, which was confirmed by the absorption spectrum. Open-circuit potential (OCP) and current-voltage (I-V) measurements showed the resulting composite had a good p-type property. CISe spherical NPs electrodeposited on the CNTs/PI membrane may have promising applications in optoelectronic nanodevices and nanotechnologies; in addition, the CNTs/PI membrane could be used as raw material for manufacturing solar cells. (C) 2011 Elsevier Ltd. All rights reserved.