光-电协同调控的高反射率全彩色液晶器件

Full-color liquid crystal device with high reflectivity by photo-electric modulation

本文利用光-电协同调控的方法获得了具有高反射率、全彩色显示的倾斜螺旋胆甾相(ChOH)器件。在液晶体系中引入一种具有左旋旋向的手性光开关switch 1,并基于相反旋向手性添加剂的手性抵消原则,使用R811来平衡switch 1发生光致Z/E异构化前后螺旋扭曲力上的差异,使体系在光照前后对其施加相同的电场强度可以反射具有相反旋向且相同波段的红-绿-蓝三色光。在此基础上,构筑了双层结构的液晶器件,对材料进行分层光-电刺激,诱导上层螺旋结构翻转,可在双层结构中分别形成左右旋结构,从而具有全反射效应,在双层ChOH液晶器件中反射率提升约60%。本研究为制备具有高反射率的全彩色电子纸器件提供了新思路,同时也为光开关材料在液晶器件中的应用提供了有益的探索。

In this work,the oblique helicoidal cholesteric(ChOH)device with high reflectivity and full color displaying was obtained by means of photo-electric cooperative regulation.By introducing a lefthanded chiral photoswitch(switch 1)into liquid crystal(LC)system,also based on the principle of chiral cancellation of the opposite handedness chiral additive,a chiral agent R811 was used to balance the difference in helical twisted power value before and after Z/E photoisomerization of switch 1,so that the system could reflect circularly polarized light with opposite handedness and the same red-green-blue colors by applying the same electric field intensity before and after light irradiations.On this basis,a double-layer LC cell was constructed,and the cell was subjected to photo-electric stimulation to induce the helical inversion of the upper layer,so that left-and right-handedness ChOH structure could be formed in the double-layer structure.As a result,the reflectance of the system was increased by around 60%in the device structure with full reflection effect.This study provides a new idea for the preparation of full-color electronic paper devices with high reflectivity,and also provides a useful exploration for the application of photoswitch materials in LC devices.