We report on a persistent internal photopolarization effect observed in C60 thin films at room temperature. This differs from the similar "photo-electret" state previously seen in some other materials by an absence of fast photodepolarization. Our oxygenated C60 thin films also exhibit persistent photoconductivity. Both phenomena are discussed within the framework of a model of photogenerated carrier trapping at deep level centers and an inhibition of their recombination due to strong distortion of the C60 molecule which is known to occur in the presence of localized charge.
- A. fullerenes
- D. electronic states (localized)
- D. photoconductivity and photovoltaics