title: Improvement in device performance from a mixture of a liquid crystal and photosensitive acrylic prepolymer with the photoinduced vertical alignment method.
abstract: In a multicomponent nematic liquid crystal (NLC) mixture of a liquid crystal (negative-type NLC) and a photosensitive acrylic prepolymer, photopolymerization upon UV irradiation induces the separation of the LC and photosensitive acrylic prepolymer layers, thereby leading to a vertical arrangement of LC molecules. In this study, we propose a simple vertical alignment method for LC molecules, by adding a chiral smectic A (SmA∗) liquid crystal having homeotropic texture characteristics to an NLC mixture solution. Measurements of electro-optical properties revealed that the addition of the SmA∗ LC not only strengthened the anchoring force of the copolymer alignment film surface, but also significantly enhanced the contrast ratio (∼73%), response time and grayscale switching performance of the device.
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan; Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors.forename: Czung-Yu
authors.initials: CY
authors.lastname: Ho
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors.forename: Fa-Hsin
authors.initials: FH
authors.lastname: Lin
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Yu-Tai
authors.initials: YT
authors.lastname: Tao
authors.affiliation: Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors.forename: Jiunn-Yih
authors.initials: JY
authors.lastname: Lee
keywords: electro-optical properties; grayscale switching; homeotropic texture; liquid crystal; photosensitive; prepolymer; vertical arrangement effect