Does the triphenylamine-based D35 dye sensitizer form aggregates on metal-oxide surfaces?

Abstract

The absorption and emission properties of the D35 organic dye sensitizer attached to zirconia and titania nanoparticles are examined. The dye-sensitized nanoparticles are prepared in the presence and absence of the chenodeoxycholic acid (CDCA) co-adsorbent to control the amount of dye adsorbed to the metal-oxide surface. The broadening of the dye's optical absorption band on the long wavelength side for layers without CDCA co-adsorbent demonstrates that J-aggregates are formed. Fast energy transfer is found to occur from the excited dye monomers to the dye aggregates. From the time-resolved fluorescence decay curves recorded for the dye attached to zirconia, the isolated dye monomer is deter..