Electro-Optic effects of organic molecule dispersed in nematic liquid crystals

Pravinraj Selvaraj^1*, Mareena Antony¹, Che-Ju Hsu¹, Chi-Yen Huang¹

¹Physics-Photonics, National Changhua University Of Education, Changhua, Taiwan

* Presenter:Pravinraj Selvaraj, email:slpravinraj@gmail.com

Abstract: N-benzyl-2-methyl-4-nitroaniline (BNA) is a common organic material with high second harmonic generation efficiency. When they are dispersed in nematic liquid crystals (LCs), different contributions to the LC devices' electro-optical properties are exhibited. BNA doping decreased the threshold voltage because of the reduced splay elastic constant and increased dielectric anisotropy of the LC mixture. The BNA-doped LC cell has a fall time that is five times faster than that of the pure one because of the decrements in the threshold voltage of the cell and rotational viscosity of the LC mixture. The decreased viscosity can be deduced from the decrements in phase transition temperature, and the LC mixture has associated order parameters. Density functional theory (DFT) calculation demonstrates that the BNA dopant strengthens the absorbance for blue light; increased dipole moment, polarizability, and polarizability anisotropy increase the dielectric anisotropy of the LC mixture, which agrees with the experimental results. BNA doping has a promising application to the fields of LC devices and displays.

Keywords: Liquid crystal, Organic molecule, BNA, Density Functional Theory