In situ photothermal deflection spectroscopy revealing intermolecular interactions upon self-assembly of dye monolayers.

We demonstrate the potential of photothermal deflection spectroscopy (PDS) to study the self-assembly of dye monolayers in situ. Beyond the determination of adsorption kinetics at specific wavelengths, PDS gains its strength from yielding UV-vis absorptance spectra of SAMs in situ, unaffected by scattering, from which supramolecular interactions can be deduced.