| Luminescent liquid crystal displays doped with fluorescent dyes have attracted great attentions recently. The brightness and color of dyes can be adjusted.Additionally, the polarizer, color filter and backlight are replaced. Then they can simplify the structure of device and increase luminescence brightness, contrast,efficiency and viewing angle, thus they are widely used in display field, etc. The dyes with high fluorescence intensity and compatibility have potential applications in the field of display, chemical and biological sensors. We designed and synthesized a novel cyanostilbene derivative and studied its luminescence properties and application in cholesteric liquid crystal (CLC).The main contents are concluded as follows:(1) In this paper, a new cyanostilbene derivative CN-AFAN was used and the absorption properties and fluorescence properties were researched. In addition, the dye has high photoluminescence intensity both in solid state and solution state. The solid fluorescent quantum yield (?F) is 0.24. It also has good compatibility with liquid crystal (2%).(2) Two optical devices have been fabricated by doping the dye into the CLC. One of them is high-contrast electrically switchable light-emitting liquid crystal displays.It can be switched among the planar state, focal conic state and homeotropic state by electric filed. It also has high fluorescence contrast (11:1) and can be switched conveniently. This device is suitable to store confidential information and can be used as a display.(3) By doping chiral ions, chiral agents and CN-AFAN into negative liquid crystal,white light CLC device also been prepared successfully. The device can be switched between the planar state, focal conic state and wide-band reflection state by electric filed. The move of chiral ions will led the gradient distribution of pitch and white fluorescent will appear. We also used the polymer network to stabilize the performance of white light devices. The device can be used in display field. |
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