Electric field and temperature dependent conductivity in PEDOT:PSS/PVA

Abstract

The charge transport in conducting polymer blends of poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) [PEDOT:PSS] and polyvinyl alcohol (PVA) at 75, 50, 25, and 12 vol. % of PEDOT:PSS is investigated in the temperature range of 300-4.2 K. The scaling fit to percolative transport [σ ∝ |f − fc|t] shows that fc is around 10% and t = 2. The temperature dependent conductivity varies from the critical regime of metal-insulator transition to variable range hopping, along with the alterations in the networks of PEDOT:PSS in PVA. The variation in the exponent (n) in electric field dependent conductivity is more significant as the volume fraction of PEDOT:PSS decreases. The value of n decreases as the thermal contribution to transport dominates, showing the competing roles of both field and temperature.