Reversible Displacement Current Generation Due to Photochromism in a Spread Monolayer: Influence of Molecular Orientation

Abstract

Reversible displacement current generation due to the cis-trans photoisomerization of AZBAA monolayers containing azobenzene derivative was investigated by alternate irradiation with UV light and visible light. The direction of the displacement current generated by irradiation with visible light depended on the area per AZBAA molecule. The direction changed consecutively from negative to positive with compression of the AZBAA monolayer formed at the air-water interface. In contrast, the change in absorption spectra of the AZBAA monolayer at the air-water interface due to the cis-trans photoisomerization was observed in the entire range of the area per molecule. Finally, it was concluded from the displacement current measurement that the orientation of the AZBAA molecules distributed on a water surface was turned by the compression.