Improvement of rewriting time of optically driven liquid crystal display by azo-dye doping

ABSTRACT

Optically driving liquid crystal display (ODLCD) uses polarized light field to control the orientation of the liquid crystal, and the display content can be maintained without external electric field, with extremely low power consumption. However, it has a long rewriting time, which is difficult to achieve industrialization. In order to improve the rewriting performance, the influence of the rotational viscosity of the mixed system of azo-dyes (SD1, MR) and nematic liquid crystal (5CB) on the rewriting speed is investigated. The experimental results show that the electro-optical properties of SD1-5CB and MR-5CB have great changes after irradiation by polarized light, among which the SD1-5CB is the best to improve the performance. With the increase of SD1 concentration, the rotational viscosity of SD1-5CB decreases significantly due to the change of cis-trans isomerization of azo-dye, and the optimal doping concentration is 0.5 wt%. In this case, the rewriting time is shortened from 45 s to 11 s, which has the potential to broaden the application of ODLCD.

GRAPHICAL ABSTRACT

KEYWORDS:

• Optically driving liquid crystal display
• rewriting time
• azo-dye
• cis-trans isomerisation

Acknowledgments

Financial support from the Natural Science Foundation of Hebei Province A2019202235 and A2023202014 are gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research is supported by the Natural Science Foundation of Hebei Province of China under Grant [NO.A2019202235]; the Natural Science Foundation of Hebei Province of China [NO.A2023202014)].