Manipulating the Switching of Liquid Crystals by Interfacial Nanotips Penetrating Polyimide Hybrid Alignment Layers

Liquid crystals (LCs) are an active area of interestfor electro-opticaldevices, and the alignment of LCs has emerged as an extremely essentialissue for LC devices. Evidence suggests that the surface topologyof alignment layers plays a key role in both tuning the tilt anglesand modulating the switching of LCs. Herein, nanotips are constructedby self-assembly of two different two-dimensional (2D) nanoflakesin PI hybrid alignment layers to modulate the switching of LCs. BothMoS(2) nanotips and Ti3C2T x MXene nanotips were observed on hybrid thin layers,but MoS2 nanotips are much thinner and taller. The hybridthin layers are highly transparent, and the nanotips penetrating thehybrid layers roughened the surface but moderately declined the surfaceenergy. LCs are strongly anchored on hybrid alignment layers, andthe nanotips were found to topologically hinder the in-plane switchingof LCs and hence accelerate the rewriting speed of optical data. Besidesthe accelerated optical rewriting speed, the surface plasmon-polariton(SPP) of nanoflakes also substantially boosted the external electricfield to switch LCs and hence remarkably diminished the operatingvoltage and likewise sufficiently shortened the response time. Inparticular, the optical rewriting time of LCs that homogeneously alignedon hybrid alignment layers with 0.5% MoS2 nanoflakes dopinghas been deduced to as short as 43.36 s, which is a decrease of 37.81%compared to that of PI alignment layers cell; LCs can be electricallydriven to switch optical data at 2.51 V and return to their originalalignment state within 24.142 ms. These results signify the promisingapplications of hybrid thin layers for both traditional LC devicesand optical rewritable LC devices.

Automated summary

Liquid crystals (LCs) are of great interest for electro-optical devices, and the alignment of LCs is crucial for their performance. Researchers have developed nanotips made of MoS(2) and Ti3C2T x MXene to modulate the switching of LCs. These nanotips penetrate the hybrid alignment layers, roughen the surface, and decrease the surface energy, leading to accelerated rewriting speed of optical data. The combination of nanotips and surface plasmon-polaritons (SPP) substantially reduces the operating voltage and response time of LC devices, showing promising applications for both traditional LC devices and optical rewritable LC devices.