Photoluminescence and Raman spectroscopy studies on polyaniline/PbI2 composite

Functionalization of PbI2 with conjugated polymers (polyaniline-emeraldine base (PANI-EB) or polyaniline-emeraldine salt (PANI-ES)) is demonstrated by Raman and luminescence studies. PbI2/PANI hybrid material was prepared by electrochemical polymerization of aniline onto the PbI2 modified Pt electrode and mechanico-chemical reaction between the two constituents. PANI interacting with the PbI2 gives rise to new Raman bands at 80,144 and 170 cm(-1). First line reveals the formation of "stacking faults" that disrupt the I-Pb-I layers stacking along the c axis by the insertion of polymer molecules. The bands at 144 and 170 cm(-1) are attributed to the vibrational mode associated with Pb-NHR ''(2) (R '' = C6H4) bond. The functionalization of PbI2 with PANI-EB brings forth the PANI-ES form. Depending on the semiconducting (PANI-EB) or conducting (PANI-ES) properties of the polymer in the PbI2/PANI intercalated material, a partial or total collection of the charges generated under band to band irradiation is revealed by photoluminescence studies. (C) 2009 Elsevier Inc. All rights reserved.