A novel photoelectrooptical effect based on Freedericksz-type transition in nematic mixtures of azoxy compounds and cyanobiphenyls

• Published in: Functional Materials
• Date: 2018
• Main Authors: Lisetski, L.N., Samoilov, A.N., Minenko, S.S., Fedoryako, A.P., Bidna, T.V.
• Format: Article
• Language: English
• Published: НТК «Інститут монокристалів» НАН України 2018
• Subjects: Characterization and properties
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/157186
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: A novel photoelectrooptical effect based on Freedericksz-type transition in nematic mixtures of azoxy compounds and cyanobiphenyls / L.N. Lisetski, A.N. Samoilov, S.S. Minenko, A.P. Fedoryako, T.V. Bidna // Functional Materials. — 2018. — Т. 25, № 4. — С. 681-683. — Бібліогр.: 10 назв. — англ.

In mixtures of nematic liquid crystals with opposite signs of dielectric anisotropy (alkylcyanobiphenyls and azoxybenzenes), a possibility of photoinduced Freedericks-type transition was realized, which could be observed both by optical transmission in a standard geometry and by changes in electric conductivity. UV irradiation leads to lowering of the planar-to-homeotropic transition threshold, and at a certain bias voltage a photoinduced transition could be realized. Trans-cis isomerization of azoxy component decreases the anisometry of its molecules, resulting in higher positive dielectric anisotropy of the material. Prospects of application of the reported effect in optoelectronic devices are discussed.