Graphene Glass Inducing Multidomain Orientations in Cholesteric Liquid Crystal Devices toward Wide Viewing Angles

Abstract

The photonic reflection of a cholesteric liquid crystal (ChLC) device depends on the spatial distribution of the orientations of their helical axes, and many orientation techniques have been developed so far. In this study, we select the hybrids of graphene directly grown on quartz glass as platforms to construct ChLC-based devices. This special design makes graphene serve as both an alignment layer and a conductive layer, thus affording a more simplified device fabrication route. We reveal that multidomain structures can be evolved for ChLCs on polycrystalline monolayer graphene on quartz glass, as evidenced by polarized optical microscope characterizations. The disparate orientations of the helical axes of ChLCs and the formation of multidomain structures are proposed to be induced by the different domain orientations of graphene, leading to a wide viewing angle of the ChLC-based devices. Moreover, the pitch of ChLCs is also observed to play a key role in the relative orientations of ChLCs. A wide viewing angle of the ChLC-based device is also detected especially in the infrared spectrum region. Briefly, this work should provoke the application of graphene glass as a perfect transparent electrode in the fabrication of liquid-crystal-based devices showing broad application potentials in intelligent laser protection and energy-saving smart windows.

Frontiers in carbon dots: design, properties and applications

“…Natural processes provide many examples where chiral compounds [163][164][165] such as chiral molecules [166][167][168] and chiral liquid crystal materials 43,[169][170][171][172] are synthesised. As a property of materials, chirality has attracted the attention of researchers for many practical applications such as chiral drug recognition, chiral molecular biology, chiral molecular biology and optical applications.…”

Oxygen-assisted direct growth of large-domain and high-quality graphene on glass targeting advanced optical filter applications

“…Of particular note, in comparison with the devices using traditional transparent conductive electrodes (e.g., indium-tin oxide (ITO), ton ~ 3.9 ms, toff ~ 129 ms, Fig. S14 in the ESM), ours possess faster switching speed and lower driving voltage, benefiting from the interaction between graphene and liquid crystal molecules [35,36]. The contrast ratio of the device also remains high at the visible light region (Fig.…”

Carbon Allotropes as ITO Electrode Replacement Materials in Liquid Crystal Devices

“…Materials are also available at comparable performance to ITO (Figure 19a), yet at still higher cost and mostly not having been scaled up to sizes and the reproducibility of industrial standard (Figure 19b). The main problem with Other applications of ITO-free LC applications with carbon-based electrodes that have been reported include cholesteric multi-domain structures for energy-saving smart windows [174], mid IR spatial light modulators [175], micro-lens arrays [176], and tuneable scattering devices [177].…”