Enhancement of Room Temperature Electrical Conductivity of Polypyrrole by Chemical Modification

Polypyrrole and polypyrrole−tetracyanoquinodinodimethane (TCNQ) have been prepared to see the energy band structure modification and associated change in the electrical and optoelectrical properties. The temperature-dependent electrical conductivity of the samples show interesting behavior, namely, higher room-temperature conductivity of polypyrrole−TCNQ and a crossover phenomenon which may be considered as a competition between two opposing factors, charge-transfer interaction and disorderness. CHN microanalysis, UV−vis absorption spectroscopy, and positron annihilation lifetime spectroscopy corroborate the findings.