InP/ZnS quantum dots doped blue phase liquid crystal with wide temperature range and low driving voltage

Jiayue Tang,Fashun Liu,Mengli Lu,Dongyu Zhao

doi:10.1038/s41598-020-75046-0

Abstract

Blue-phase liquid crystals (BPLCs) are regarded as potential materials for the exploitation of next-generation optical devices due to the rapid response, wide viewing angle, and simple industrial production procedures. However, practical application of traditional BPLCs is limited by their narrow temperature range and high driving voltage. Herein, we demonstrated that doping of chiral molecular isosorbide hexyloxybenzoate (R811) into BPLCs is able to increase the temperature range. More importantly, addition of InP/ZnS quantum dots (QDs) with oleylamine surface groups could also effectively broaden the temperature range of the BPLCs further while decreasing the driving voltage, which is attributed to the quantum dot trapped by BPLCs lattice defect that reduces its free energy. Since the trapped quantum dot subsequently forms a local electric field under electric field, the effective electric field of the surrounding liquid crystal molecules is enhanced and the rotation of the liquid crystal molecules is accelerated. Specially, the temperature range is widened by 1.4 °C, and the driving voltage is reduced by 57%, under the optimal concentration of R811 and lnP/ZnS QDs. The accomplishment we proposed in this work is a prospective optimization which makes the practical application of blue phase liquid crystals one step closer.

Highlights

Blue-phase liquid crystals (BPLCs) are regarded as potential materials for the exploitation of nextgeneration optical devices due to the rapid response, wide viewing angle, and simple industrial production procedures
When the concentration of R811 continued from 33 wt%, the temperature range of BPLC began to decrease, after 44 wt%, blue phase liquid crystals no longer appeared, which may be caused by an excess of R811
The mechanism of InP/ZnS QD broadening the temperature range of blue phase liquid crystal may be that the quantum dots in free motion can be trapped by defects in BPLC, and the quantum dots self-assembly occupies the defects in the blue phase lattice, which makes the volume around the defects compressed and the free energy reduced

Summary

Introduction

Blue-phase liquid crystals (BPLCs) are regarded as potential materials for the exploitation of nextgeneration optical devices due to the rapid response, wide viewing angle, and simple industrial production procedures. Based on the advantages of QDs doping, in this paper, we doped InP/ZnS QDs (Fig. S1) into BPLCs, and studied the effects of the QDs on BPLC temperature range and driving voltage.

Results

Conclusion