Polyoxometalates (POM), also known as polyanionic metal oxide clusters, have recently become one of the focus researches in science and technology. In this study, a nanocomposite film electrochemically formed by combining the Keggin type polyoxometalate (K7-xNaxPW11O39 center dot 14H(2)O) (POM) and star shaped carbazole derivative (N-2, N-4, N-6-tris (9-ethyl-9H-carbazol-3-yl)-1,3,5-triazine-2,4,6-triamine denoted as T3AC. A synergistic interaction between carbazole and POM derivative has been noticed for the first time in the literature. Optical properties of the POM/T3AC solution have been changed due to this interaction which not observed in other electroactive monomers such as pyrrole, thiophene, indole etc. More importantly electrical and optical properties of the nanocomposite structure synthesized electrochemically from this solution have been improved. (C) 2019 The Electrochemical Society.