Microscopic investigation of the poly(9,9-dioctylfluorene) photoluminescence dependence on the deposition conditions by confocal laser microscopy

We studied the microscopic dependence of poly(9,9-dioctylfluorene) photoluminescence (PL) on the deposition conditions. We show that in films spin coated from chloroform phase separation of beta and glassy phases is present, with micrometric beta phase clusters covering about 6% of the sample surface. The exposure to toluene vapors leads to the disappearance of the beta phase clusters, but increases the beta phase content in the films due to swelling induced polyfluorene chain planarization. The deposition from toluene solution leads to nonuniform PL intensity, dominated by the beta phase emission, attributed to an interplay between aggregation during the solvent evaporation and solvent swelling induced chain planarization. (c) 2006 American Institute of Physics.