Photoinduced optical absorption changes in the vacuum-ultraviolet (VUV) spectral range have been measured in poly(methylphenylsilylene) thin films under varied excitation photon energies and local atmospheric environments. Spectral changes in resonances associated with both the linear chain Si-Si backbone and the side groups of the hybrid structure are consistent with the photodisruption of backbone topology. These effects are more pronounced under a higher energy photon exposure (5.10 eV) resonant with the fundamental π - π* transition of the phenyl moiety. An aerobic environment also favors more dramatic bleaching of VUV absorption in these materials. Finally, the present study enables a Kramers-Kronig analysis of absorption change from the visible to the VUV. These results do not adequately describe the photoinduced refractive index changes measured at 632.8 nm via ellipsometry, indicating the presence of other contributions to the index modifications observed.
ASJC Scopus subject areas
- Physics and Astronomy(all)