Highly soluble poly(2,7-carbazolenevinylene) for thermoelectrical applications: From theory to experiment Isabelle Le ´vesque a,b, * , Xing Gao a , Dennis D. Klug a , John S. Tse a , Christopher I. Ratcliffe a , Mario Leclerc b a Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ont., Canada K1A 0R6 b Universite ´ Laval, De ´partement de chimie, Quebec, Que., Canada G1K 7P4 Received 30 August 2004; received in revised form 11 November 2004; accepted 12 November 2004 Available online 18 July 2005 Abstract A new highly soluble derivative of poly(2,7-carbazolenevinylene) was synthesized, bearing alkyl side chains in the 3,6 positions. The polymer synthesized was characterized by optical, electrochemical and electrical measurements. The sta- bility towards chemical doping at room temperature is investigated. The Seebeck coefficients at room temperature are measured for different doping levels and compared to poly(3-decylthiophene). At high doping level, the Seebeck coef- ficient is around 200–250 lV/K, which is one order of magnitude higher than poly(3-decylthiophene). At low doping level, the Seebeck coefficient reaches 600 lV/K. The carbazolenevinylene polymer is not very conductive, the highest conductivity obtained being 5 · 10 3 S/cm. The electronic band structure and the Seebeck coefficients at room temper- ature are calculated and compared to experimental results. Crown Copyright Ó 2005 Published by Elsevier B.V. All rights reserved. Keywords: Conjugated polymers; Carbazole; Thermoelectricity; Seebeck coefficient; Band structure calculations 1. Introduction Conjugated polymers are known for their inter- esting optical and electrical properties. They have been extensively studied for their applications as sensors, light-emitting diodes, transistors and pho- tovoltaic cells [1–7]. The use of such semi-conduct- ing polymers for thermoelectrical applications have also been studied using polyacetylene, poly- thiophene, polyaniline and polypyrrole [8–16]. The processability of such materials has been im- proved over the years by the use of novel synthetic methods allowing the incorporation of flexible side chains, which allow the solubilization of the poly- mers in common solvents. Their advantages are 1381-5148/$ - see front matter. Crown Copyright Ó 2005 Published by Elsevier B.V. All rights reserved. doi:10.1016/j.reactfunctpolym.2004.11.008 * Corresponding author. Tel.: +418 656 2131x6555; fax.: +418 656 7916. E-mail address: isabelle.levesque@chm.ulaval.ca (I. Le ´v- esque). Reactive & Functional Polymers 65 (2005) 23–36 REACTIVE & FUNCTIONAL POLYMERS www.elsevier.com/locate/react