Structural, optical and electrical properties of polypyrrole in an ionic liquid

Structural, optical and dielectric properties of polypyrrole (Ppy) were studied. Structural and optical properties of Ppy were studied using FT-IR and UV–visible spectrophotometer. Optical band gap ( E g ) values of Ppy in an ionic liquid were increased with composite raw material. Moreover, the relation between ( E g ) and refractive index ( n ) was estimated by Moss relation and then the relation between n and optical high-frequency dielectric constant ( ε ′ ) were calculated. The experimental dielectric constant values of Ppy were lower than the theoretical values calculated from the relation. The alternating current (ac) conductivity shows that the compound is a typical organic semiconductor, as its conductivity increases with increasing frequency and the obtained results have been discussed in terms of the correlated barrier hopping (CBH) model. The absorption coefficient effects of the Ppy samples exhibited nearly-Debye type process. The calculated α and τ 0 values are ~0.14 and ~0.01587 s, respectively.