Effects of Si5+Ion Irradiation on Poly(3-methyl thiophene) Films

Poly(3-methyl thiophene) has been synthesized by the chemical oxidation polymerization method using FeCl3. The powder has been dissolved in CHCl3 and thin films of thickness 2 mu m are prepared on glass and Si substrates. The polymerization has been confirmed by FTIR spectrum. The films are irradiated by 60MeV Si5+ ions at different fluences and modifications in optical, electrical and structural properties are studied. FTIR spectra show methyl group evolution after irradiation. The optical band gap decreases after irradiation and dc conductivity increases four orders of magnitude after irradiation at the highest fluence. The conduction mechanism has been found mainly by band conduction.