Electrical transport in pristine and heavily doped polyacenic materials

Abstract
Experimental studies of electrical transport properties have been performed with respect to pristine and heavily doped polyacenic materials prepared by pyrolytic treatment of phenol-formaldehyde resin. Four kinds of the pristine samples prepared under different temperatures were employed. It is shown that temperature dependences of electrical conductivity and of thermoelectric power suggest that the conduction mechanism in the samples varies from the three-dimensional variable-range-hopping to the nearly-filled-band metallic regime with increasingly higher values of the chosen pyrolytic temperature.