Evidence of high charge mobility in photoirradiated polythiophene–fullerene composites

Abstract

Interpenetrating networks of polythiophenes and fullerene derivatives give rise to charge transfer after irradiation with visible light. The resulting radical ion pairs have been studied by time-resolved EPR spectroscopy. At low temperatures (20 K), the radical pairs are spin correlated and locked at a distance of 27.1 Å, whereas an increase of temperature causes the electron and the hole to move further away from each other.