Chiral dopant effects on the birefringence and transmittance of nematic and polymer-stabilized liquid crystals for future applications

Abstract

Nowadays, liquid crystals with optically important properties have attracted the attention of various scientific groups. In this case, various factors such as applied electric fields, and doped molecules' characteristics in pure liquid crystals are important in controlling their behavior in different experiments. In this research, the effect of chiral molecules on the electric field-induced birefringence of nematic molecules was studied. Based on the results, the nematic liquid crystal with high contribution of chiral molecules (27 wt%) shows considerable birefringence. Moreover, transmittance characteristics of cholesteric, and polymeric liquid crystals with 27 wt% of chiral molecules at different applied electric fields were studied. In this case, polymer networks can increase the transmittance spectral bandwidth. Additionally, coating the cells with a thermal pigment layer leads to the reduction of the transmittance of light. Therefore, these materials with high birefringence and controllable transmittance can be used as light-controlling future optical devices.