Suppression Mechanism of the Photodegradation of J-Aggregate Thin Films of Cyanine Dyes by Coating with Polysilanes
journal contributionposted on 14.04.2011 by Hiroaki Horiuchi, Syohei Ishida, Ken-ichi Matsuzaki, Katsuhiko Tani, Takuya Hashimoto, Hiroki Hotta, Kin-ichi Tsunoda, Takuo Kodaira, Tetsuo Okutsu, Hiroshi Hiratsuka
Any type of content formally published in an academic journal, usually following a peer-review process.
To clarify the suppression mechanism of the photodegradation of J-aggregate thin films of cyanine dyes induced on the coating with polysilanes, we have studied photochemical and electrochemical properties of composite films of J-aggregate of cyanine dyes and polysilanes. We have determined onset oxidation potentials of both J-aggregate thin films and polysilane thin films by employing an ITO electrode slab-optical waveguide spectroscopic system combined with an electrochemical measurement system. It has been clarified that photodegradation efficiency decreases with an increase in the onset oxidation potential of J-aggregate, indicating that the photodegradation of J-aggregate thin film mainly proceeds via its radical cation produced from the first excited singlet state, and polysilanes donate an electron to the radical cation to suppress the photodegradation. Film thickness and molecular orientation of polysilane were found to be important factors to suppress the photodegradation.