Balanced electro-optical properties and off-axis haze performance of a polymer-dispersed liquid crystal film via refractive index matching

Meina Yu; Jianjun Xu; Luoning Zhang; Qian Wang; Cheng Zou; Yanzi Gao; Huai Yang

doi:10.1039/d3cp03024e

Balanced electro-optical properties and off-axis haze performance of a polymer-dispersed liquid crystal film via refractive index matching

Phys Chem Chem Phys. 2023 Sep 13;25(35):23770-23782. doi: 10.1039/d3cp03024e.

Authors

Meina Yu¹, Jianjun Xu^{2

3}, Luoning Zhang¹, Qian Wang¹, Cheng Zou^{1

2}, Yanzi Gao¹, Huai Yang^{1

2

4}

Affiliations

¹ Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing, China. yumeina@ustb.edu.cn.
² Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China.
³ School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, China.
⁴ School of Materials Science and Engineering, Peking University, Beijing, China.

PMID: 37622171
DOI: 10.1039/d3cp03024e

Abstract

As a type of smart dimming film, polymer-dispersed liquid crystals (PDLCs) show great prospects in the fields of indoor partition, electronic curtains, and automobile windows. However, its high off-axis haze greatly impacts the application scope. This obvious shortcoming is mainly caused by the serious mismatch between the effective refractive index of the liquid crystal (n_eff) and the refractive index of the polymer matrix (n_p) at large viewing angles. Thereby, factors affecting the viewing angle of a PDLC film are analyzed in this research, including the birefringence of the liquid crystal (Δn), film thickness, and the refractive index of the polymer matrix (n_p). Balanced electro-optical properties are guaranteed simultaneously. It is found that high on-state transmittance and low off-axis haze can be achieved at large viewing angles in the suggested optimized case where Δn is within the range of 0.1-0.13; the film thickness is between 20 μm and 15 μm; and n_p approaches n_o but the difference does not exceed 0.03.