  Simple vacuum evaporation technique for deposition of dyes on various solid
surfaces has been developed. The method is compatible with conventional
solvent-free nanofabrication processing enabling fabrication of nanoscale
optoelectronic devices. Thin films of fluorescein were deposited on glass,
fluorine-tin-oxide (FTO) coated glass with and without atomically layer
deposited (ALD) nanocrystalline 20 nm thick anatase TiO2 coating. Surface
topology, absorption and emission spectra of the films depends on their
thickness and the material of supporting substrate. On a smooth glass surface
the dye initially formes islands before merging into a uniform layer after 5 to
10 monolayers. On FTO covered glass the absorption spectra are similar to
fluorescein solution in ethanol. Absorption spectra on ALD-TiO2 is red shifted
compared to the film deposited on bare FTO. The corresponding emission spectra
at {\lambda} = 458 nm excitation show various thickness and substrate dependent
features, while the emission of films deposited on TiO2 is quenched due to the
effective electron transfer to the semiconductor conduction band.
