Electrosynthesized cadmium indium selenide (CdIn2Se4) thin films were (photo) electrochemically analyzed by current-voltage characteristics, photoresponse, speed response, electrochemical impedance study, and capacitance-voltage characteristics. The improved phottdsleve;oconversion efficiency of electrosynthesized CdIn2Se4 thin film-based photoelectrochemical cell explained with the help of theoretical modeling of energy band diagram and equivalent circuit model of the impedance spectra of the photoelectrochemical cell. (C) 2016 Elsevier B.V. All rights reserved.