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Updated: May 8, 2026
An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation
Published on: February 27, 2019
All-optically controllable and highly efficient scattering mode light modulator based on azobenzene liquid crystals
Yen-Chen Liu1, Ko-Ting Cheng, Yuan-Di Chen
1Department of Photonics, National Cheng Kung University, Tainan 701, Taiwan.
Abstract:
The present study reports that isothermal phase transition induced by photoisomerization of azobenzene liquid crystals (azo-LCs) from trans- to cis-isomers results in the dissolution of poly(N-vinylcarbazole) (PVK) into azo-LCs. Transparent (scattering) states can be demonstrated using uniform (rough) morphologies of PVK generated by slow (rapid) phase separation of PVK and azo-LCs from cis- to trans-isomers. The PVK films were examined in detail using scanning electron microscopy. Scattering performance resulting from the rough PVK surface induced micron-sized LC domains, and transparent performance resulting from the reformed uniform PVK surface can be optically and reversibly switched. Finally, all-optically controllable and highly efficient (contrast ratio of 370:1) scattering mode light modulators based on azo-LCs and PVK films were demonstrated.
