Electrical conductivity and thermoelectric power of polypyrrole with different doping levels

Abstract The electrical conductivity and absolute thermoelectric power of the conducting polymer polypyrrole have been measured between approximately 4 K and 350 K. Normally-doped films had a conductivity of 26 Ω −1 cm −1 , whilst lightly-doped films had a conductivity of 8 Ω −1 cm −1 . The Mott variable-range hopping model for electrical conductivity is obeyed at higher temperatures for both types. The thermoelectric power is approximately linear in temperature, reaching about 5 μV K −1 at 200 K, but is sublinear at higher temperatures and becomes constant above about 300 K. The Kuivalainen model, which explains the reported anomaly between optical and d.c. electrical conductivity, gives a good fit to the experimental data.

[1]  Monte Carlo method for quarks in lattice gauge theories , 1983 .

[2]  J. F. Kwak,et al.  Polypyrrole: An electrochemically synthesized conducting organic polymer , 1980 .

[3]  C. S. Jacobsen,et al.  Characterisation of the transport properties of conducting polypyrrole films , 1987 .

[4]  L. Friedman.  Hall conductivity of amorphous semiconductors in the random phase model , 1971 .

[5]  D. Tanner,et al.  Role of Solitons in Nearly Metallic Polyacetylene , 1983 .

[6]  Joel S. Miller,et al.  Extended Linear Chain Compounds , 1983 .

[7]  E. Gogu,et al.  Electric conductivity and thermoelectric power of various polypyrroles , 1987 .

[8]  Ping Sheng,et al.  Fluctuation-induced tunneling conduction in disordered materials , 1980 .

[9]  R. Roberts.  The absolute scale of thermoelectricity , 1977 .

[10]  J. Tanaka,et al.  Electrical and Optical Properties of a Stable Synthetic Metallic Polymer: Polypyrrole , 1981 .

[11]  N. Mott,et al.  Electronic Processes In Non-Crystalline Materials , 1940 .

[12]  R. Deltour,et al.  Electrical conductivity of I2-doped polyacetylene , 1981 .

[13]  H. Fritzsche.  Optical and electrical energy gaps in amorphous semiconductors , 1971 .

[14]  H. Stubb,et al.  Thermoelectric Power in Inhomogeneous Metallic Polymers , 1984 .

[15]  B. D. Malhotra,et al.  Recent studies of heterocyclic and aromatic conducting polymers , 1986 .

[16]  J. C. Scott,et al.  The evidence for bipolarons in pyrrole polymers , 1984 .

[17]  Nevill Mott,et al.  Electrons in disordered structures , 2001 .