A metal oxygen molecular cluster compound has been utilized for the preparation of organic-inorganic nanocomposite film by a sol-gel method. The entrapment of these cluster compounds in a composite film has been characterized by various physico-chemical techniques. The entrapped metal oxygen cluster stabilizes its energy levels, which is evidenced from the change in redox potential and band gap. The rectification phenomenon of composite films is attributed to the embedded cluster compounds. The rectification behaviour of the composite film, which is due to the charge transfer from molecular cluster and the electrode, has been studied. © 2008 Elsevier B.V. All rights reserved.