Self-condensation of the amphiphilic fluorene trimer occurs in the solvent mixture, giving pure “green” fluorescent nanoparticles with controlled radii of 20−100 nm. The origin of the green fluorescence is attributed to the excimer emission via excitation of aggregated dimer structures in the nanoparticles rather than the keto-defects. The present study also suggests the possibility of spectral tuning of emissions from oligofluorene aggregates.
