| dc.description.abstract | Electrochromic devices have attracted remarkable attention in the display field due to their low energy consumption, high contrast, and excellent flexibility. This thesis attempts to apply electrochromic characteristics to liquid crystal (LC) displays by using the electrochromic LC, SLC1717. In the presence of a direct current (DC) electric field, SLC1717 undergoes a redox reaction with the ionic liquid [Bmim][NTf2], and the color of SLC1717 will turn to magenta from colorless after its oxidation process. This study investigates the relation between the colored state (oxidized state) of SLC1717 and the concentration of the ionic liquid [Bmim][NTf2], and proposes the optimal concentration ratio is 98 wt% SLC1717 and 2 wt% [Bmim][NTf2], which possesses the maximum dynamic range of transmission (57.33%) at the wavelength of absorption peak (518.4 nm) with the application of a DC electric field. According to the experimental results about the electrochromic characteristics of SLC1717, it was observed that multiple or long-time applications of DC electric field cause [Bmim][NTf2] to provide SLC1717 with an anchoring of vertical alignment and thereby disrupt the homogeneous alignment of the LCs, indicating that the anchoring provided by the coated homogeneous alignment film is disrupted. To stabilize the homogeneous alignment of the adopted LCs, the polymer network structures were introduced and analyzed for their stabilization effect. In the polymer-stabilized electrochromic LCs with a higher concentration of [Bmim][NTf2] (2 wt%), multiple or long-time applications of DC electric field lead to scattering. The scattering drawback is speculated that the formation of multi-domains from the competition of vertical and homogeneous alignment anchoring. Therefore, we reduced the concentration of [Bmim][NTf2] in the polymer-stabilized electrochromic LCs to reduce the anchoring force from the spontaneous vertical alignment and thereby overcomed the scattering problem. The above results were also verified through polarized optical microscopy and photographs. Finally, we doped AC1 into the polymer-stabilized electrochromic LCs to evaluate the color changes by dichroic dyes and electrochromic LCs. According to the guest-host effect, the color change of AC1 can be controlled by using alternating current (AC) electric fields, while that of the oxidized state of SLC1717 can be controlled by using DC electric fields. This allows the device to simultaneously exhibit both the electrochromic characteristics and the electro-optical properties of LCs. | en_US |