A drop-casted thin film consisting of a Keggin-type polyoxometalate cluster K3PMo12O40 mixed with the semi-conducting poly(N-vinylcarbazole) (PVK) was deposited on top of ITO substrates. The resulting hybrid organic/inorganic film was characterized by electrochemistry, FT-IR spectroscopy, microscopies and spectroelectrochemistry. Interestingly, an electrochromic behavior could be evidenced from the resulting composite. (C) 2018 Elsevier B.V. All rights reserved.