Sd. Rughooputh et C. Fite, CHARGE STORAGE IN A SOLUBLE CONDUCTING POLYMER, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 231, 1993, pp. 215-222
ESR measurements and spectroscopic studies have been carried out on fi
lms of a soluble conducting polymer, poly (3-hexylthiophene) [P3HT], p
-doped electrochemically. The nature of the lowest energy charge stora
ge configurations, determined by these studies, arc found to be spinle
ss bipolarons for both doping methods. The results, when contrasted wi
th similar studies performed on P3HT (in solution) and on polythiophen
e, suggest that the long alkyl substituents on the thiophene unit of t
he P3HT are responsible for some kind of localization phenomenon preva
iling in the beta-substituted systems. At temperatures below about 150
K, spins become localized.