The thin films of pyronin B (PyB) and pyronin Y (PyY) mixed with poly(vinyl sulphate) (PVS) on glass
substrate from aqueous solution were fabricated using a simple spin-coating film technique. The photophysical
properties of the thin films were examined by UVeVis, steady-state fluorescence and timeresolved
fluorescence spectroscopy techniques. The dye thin films on the glass substrate were prepared
at various [PVS]/[dye] ratios. The interactions of pyronin dyes with PVS caused the formation of
monomeric and H-aggregate thin films of the dyes. H-aggregates of pyronin dyes in the thin film
quenched their fluorescence intensities while the monomeric dye films have strong fluorescence.
Moreover, the presence of H-aggregates in the thin film also decreased the fluorescence lifetimes of dyes.
The morphological variations in the thin films depending on the dye concentration were investigated by
AFM. The morphological analysis of the thin films revealed that the thin films including H-aggregates
were predominant in fibril-like structures while the monomeric thin films displayed the same morphologies
compared to that observed in pristine PVS film. When the spectroscopic and morphological
results were evaluated, it was concluded that H-aggregates of pyronin dyes were formed due to the
adsorption of the dyes on PVS backbone.