Combined electric and photocontrol of selective light reflection by oblique helicoidal cholesteric doped with azobenzene derivative

ORAL

Abstract

A cholesteric liquid crystal (ChLC) composed of flexible dimeric molecules shows an oblique helicoidal state (ChOH) in the presence of an electric field. By controlling the ChOH pitch P by the electric field, one can shift the wavelength of the selective reflection (transmission) of light in a broad spectral range, from UV to IR. In this work, we demonstrate that a combined action of the electric field and UV irradiation could continuously tune the pitch of a ChOH material doped with photosensitive azobenzene molecules capable of trans-cis isomerization. At a fixed voltage, UV irradiation causes a gradual redshift of the reflection wavelength by about 100 nm for the explored composition. The dynamic scenarios of the radiation-induced changes are described by kinetic equations. The phenomenon can find applications such as smart windows, lasers, optical filters, and sensors of UV intensities/doses.

*The work was supported by the National Science Foundation grant ECCS-1906104.

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Presenters

  • Kamal Thapa

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

Authors

  • Kamal Thapa

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Olena Iadlovska

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA
    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Hari Krishna Bisoyi

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Daniel Paterson

    • Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, AB24 3UE Scotland, United Kingdom

  • John Storey

    • Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, AB24 3UE Scotland, United Kingdom

  • Corrie T. Imrie

    • Department of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, AB24 3UE Scotland, United Kingdom

  • Quan Li

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • Sergij V Shiyanovskii

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA
    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA

  • O Lavrentovich

    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242, USA
    • Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA
    • Department of Physics, Kent State University
    • Advanced Materials and Liquid Crystal Institute, Department of Physics, Materials Science Graduate Program, Kent State University
    • Department of Physics and Advanced Materials and Liquid Crystal Institute, Kent State University
    • Advanced Materials and Liquid Crystal Institute, Kent State University