Author(s)

Sotirios Sakkopoulos, Evangelos Vitoratos

Department of Physics, University of Patras, Patras, Greece.

The conductivity difference Δσ between two similar PEDOT:PSS films, 120 nm thick, heated by 5 and 15 K/min from 80 to 440 K, the one under inert He and the other under ambient air gives an approximate measure of the influence of oxygen and moisture on the conductivity vs temperature T. The resulting curves Δσ = f(T) exhibit three different regions: at temperatures from 80 to 145 K for heating rate 5 K/min and from 80 to 200 K for 15 K/min, an intense degradation of the sample under ambient atmosphere was revealed by the abrupt increase of the difference of the conductivities between He and atmospheric air. At intermediate temperatures from 145 to 380 K for 5 K/min and 200 to 400 K for 15 K/min, the conductivity difference remains basically constant indicating a stabilization of the damage produced by oxygen and moisture. Finally, for temperatures higher than 380 to 400 K the degradation increases again. An explanation of this behavior is proposed based on the hydrophilic character of the PSS and the destructive role of oxygen at high temperatures. Moreover, the isotherms σ = σ(t), where t is the heating time, at 443 K, under inert He and under atmospheric air for one hour verify the significant role of oxygen and moisture on the electrical conductivity. Under He the conductivity increases monotonically with t, but under ambient air factors the conductivity competes with others decreasing it producing a maximum at about t = 10 min.

Conducting Polymers; PEDOT:PSS; Thermal Treatment; Organic Electronics

Sakkopoulos, S. and Vitoratos, E. (2014) Differentiation of the Aging Process of PEDOT:PSS Films under Inert Helium and Ambient Atmosphere for Two Different Rates of Thermal Treatment. Open Journal of Organic Polymer Materials, 4, 1-5. doi: 10.4236/ojopm.2014.41001.