Direct current conductivity studies on poly(3-methyl thiophene)

The direct current (dc) conductivity of poly(3-methyl thiophene) was measured in the temperature range of 77–300 K. The observed dc conductivity data were analyzed in the light of Mott’s variable range hopping model. Different Mott’s parameters such as characteristic temperature (T ₀), average hopping distance (R), average hopping energy (W), and density of states at the Fermi level (N E _F ]) were evaluated. By taking the inverse of the coefficient of exponential decay of the localized states involved in the hopping process as 0.5 nm, a realistic value of density of states at the Fermi level (N E _F ]) was obtained that agrees well with the values reported earlier for other conjugated polymers.