Electroabsorption studies of structurally modified fullerene thin films

Abstract

The excited-state properties of C 60 have been extensively studied in recent years through a number of processes and a good understanding of the active processes has begun to emerge. However, a number of key questions remain about the nature of the inter- and intra- molecular excited states of C 60. The application of Electroabsorption (EA) spectroscopy to the study of the charge transfer characteristics of C 60 has been shown to be an extremely valuable probe of these excited states. However, the effect of controlling the relative contributions from inter- and intra-molecular interactions has not been, thoroughly investigated. This work hopes to extend the knowledge base by monitoring the changes in the electroabsorption spectrum of fullerene thin films which are subjected to thermal annealing, a processes known to modify the electronic properties of solid state C 60. It has been shown by comparison that while there is a large pronounced change in the absorption spectrum of annealed fullerene films, there is little or no change in the electroabsorption spectrum.