Fluorescence spectra of poly(di-n-hexylsilane)/TiO2 nanoparticle hybrid film

The interaction between poly(di-n-hexylsilane) (PDHS) and TiO2 nanoparticle was studied based on the temperature dependence of the fluorescence of a PDHS/TiO2 nanoparticle hybrid film. The polysilane is a suitable probe to investigate a guest polymer-host matrix interaction because the photophysical properties of polysilanes remarkably depend on the conformation of the σ-conjugated Si-Si chain. The PDHS/TiO2 nanoparticle hybrid film showed a fluorescence band assigned to a disordered structure even at 80 K whereas only the fluorescence band of an ordered structure was observed for the PDHS film at 80 K. The disordering of the Si-Si main chain was explained by the perturbation of the n-hexyl side chain in the neighborhood of the TiO2 nanosurface. The non-radiative deactivation of the excited state via the disorder-induced local potential minima was suggested by the temperature dependence of the fluorescence intensities of the disordered and ordered structures in the temperature region from 80 to 160 K.