ABSTRACT
The combination of photochromism and electrical properties in diarylethene (DA) polymers were investigated. Photoswitching function could be introduced into a polymer by incorporating 2,3-bis(2-methylbenzo[b]thiophene-3-yl)hexafluorocyclopentene (BTF) unit plus p-phenylene vinylene (PPV) unit alternatively. The photochromic film of BTF-PPV polymer become dark colored upon exposure to a UV light because π-conjugation delocalizes between the π-conjugative groups and the new absorption band centered at 570 nm was observed from the colored film. In dark the photochromic electrode coated with BTF-PPV copolymer did not show current generation. Upon exposure to UV, large incident photon-to-current generation was observed with the quinone/hydroquinone carrier couple under a bias potential of 165 mV (vs. Ag/AgCl). By optical modulation, a reversible photocurrent generation was observed from the photochromic electrode. On the otherhands, DA polymers derived from 2,3-bis(2-methyl-3-thienyl)hexafluorocyclopentene (TF) and PPV showed no photocurrent generation, indicating photodecomposition of the closed isomer.
Acknowledgments
This work was financially supported by the Ministry of Science and Technology (MOST) of Korea and the grant from Yonsei University.