Charge transport and contact resistance in coplanar devices based on colloidal polyaniline dispersion

The charge transport properties of thin films prepared from colloidal dispersion of polyaniline stabilized by poly(N-vinylpyrrolidone) (PANI/PVP) have been investigated. The electrical characterization of coplanar device comprising of gold electrodes and PANI/PVP film deposited by spin coating served to gain insights into the contact and bulk resistance. The films prepared from PANI/PVP colloidal dispersion show high stability over a large temperature range. Temperature dependent measurements in the range from 90 to 350 K reveal that the charge transport can be described by a three-dimensional variable-range hopping mechanism as the dominant mode in the films. The stability of the films cast from dispersion within a large temperature range opens the possibility of the application as a polymer semiconductor layer in sensors and charge-transport interlayer in organic solar cells.