SHI irradiation effects on electrical and optical properties of PPy-SnO2 nanocomposite

The films of polypyrrole-tin oxide (PPy-SnO2) nanocomposites were synthesized by chemical oxidative polymerization technique. These films were irradiated with 90-MeVO7+ ions at the fluences of 5 x 10(10), 1 x 10(11), 5 x 10(11), and 1 x 10(12) ions/cm(2). X-ray diffraction studies show that microstrain and domain crystallite size of SnO2 nanoparticles in PPy matrix increase with the increase of ion fluence, resulting in highly ordered PPy-SnO2 nanocomposites. TGA analysis shows that the SnO2 nanoparticles inhibit the degradation of PPy, thereby enhancing the thermal stability of the PPy-SnO2 nanocomposites. DC electrical conductivity is found to increase with the increase of fluence and conduction mechanism follows a one-dimensional variable-range hopping model. AC electrical conductivity also increases with the increase of ion fluence and obeys correlated barrier-hopping model. I-V characteristics of the PPy-SnO2 nanocomposites exhibit Schottky barrier formation at the PPy/SnO2 interface. The photoluminescence intensity of the PPy-SnO2 nanocomposite increases with the increase of ion fluence, which can be attributed to the thermal detrapping of charge carriers owing to the enormous energy transfer during swift, heavy-ion irradiation. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim