Schottky barrier diode devices were fabricated in a sandwich configuration with a blend film consisting of a conducting polymer, poly(2,5-dimethoxyaniline), PDMA in an insulating matrix, polyethylene oxide (PEO). The influence of two different dopants, sulphate anion (SA) or methane sulfonate anion (MSA), in the electronic properties of the device was followed using the devices: ITO/PDMA (SA)-PEO/Al and ITO/PDMA (MSA)-PEO/Al. Current (I)-Voltage (V) characteristics were recorded for making a comparative evaluation of the electronic and junction properties of the devices. The junction and electronic parameters were analyzed and compared in the light of differences in the electronic state, morphology and transport of carriers. The device turn on voltage was found to be higher for Al/PEO-PDMA (MSA)/ITO (similar to3.0 V) in comparison to Al/PEO-PDMA (SA)/ITO (similar to2.85 V). The electronic states of PDMA doped with SA or MSA dopant were ascertained by optical UV-Visible spectroscopy. AC-impedance measurements were made for the devices and the values of bulk resistance (R-c), depletion resistance (R-d) and depletion layer width (W) were deduced through a proposed equivalent circuit. W for the device with PEO-PDMA (MSA) is more (similar to24 nm) than the device with PEO-PDMA (SA) (similar to8.5 nm). The observed higher OB for PDMA-PEO (MSA) is consistent with this observation. (C) 2004 Elsevier B.V. All rights reserved.