Electrical properties of conducting polypyrrole films functionalized with phthalocyanine

Polypyrrole films containing phthalocyanine were deposited by direct electr ochemical deposition method using mixed solvent system (NMP:H2O) with H2SO4 (0.1 M). The films obtained were characterized by conventional techniques such as FT-IR and UV-VIS, which confirmed the incorporation of phthalocyani ne. The presence of Cu(2p) core level peak in the ESCA studies also confirm ed the incorporation of phthalocyanine in these films. The electrical condu ctivity was found to increase with the increase of phthalocyanine concentra tion in the electrolyte. Even for a moderate increase of CuPc (from 1.0 to 2.0 mol%) in the PPy films, there is a drop in activation energy from 0.133 to 0.08 eV. Sensitivity measurements show that the CuPc containing PPy fil ms are selectively more sensitive to the nitrogen dioxide vapours. The C-V studies carried out on these films under illumination show that the photoch emical response in electrochemical mode increases due to the presence of ph thalocyanine. The cathodic peak at -700 mV, which is associated with the ph thalocyanine, becomes prominent under illumination due to photogenerated ca rriers. (C) 2001 Elsevier Science B.V. All rights reserved.