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

Abstract

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 Β and glassy phases is present, with micrometric Β phase clusters covering about 6% of the sample surface. The exposure to toluene vapors leads to the disappearance of the Β phase clusters, but increases the Β 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 Β phase emission, attributed to an interplay between aggregation during the solvent evaporation and solvent swelling induced chain planarization. © 2006 American Institute of Physics.