DC transport studies of poly(benzimidazobenzophenanthroline) a ladder-type polymer

The room- temperature electrical conductivity of poly(benzimidazobenzophenanthroline) dramatically increases when heated to 600 K by more than six orders in magnitude. The evolution of this significant increase in conductivity is studied closely. The conductivity prior to exposure to the high temperature is compared with postheated samples and analyzed in terms of activated and hopping models. The thermally induced electrical conductivity is studied for different geometries and significant anisotropic features are observed. The variation in the thermally induced conductivity with respect to the ambient conditions is also correlated with the structure. The results reveal contribution of surface processes in the electronic transport