In situ electron paramagnetic resonance study of spin dynamics in an iodine-doped poly(thiophene) derivative

Spin dynamics in an iodine-doped poly(thiophene) derivative, poly(3-butylthiophene-2,5-dyle), has been studied by means of in situ electron paramagnetic resonance (EPR) and conductivity measurements. As a result of closely monitoring the doping and dedoping processes, in addition to the narrow polaron EPR signal, an additional one, with a relatively broad linewidth, was observed in heavily doped samples and attributed to a strong polaron spin–spin correlation.