Research On Flexible Liquid Crystal Display Based On Nanoparticles Doped PI

After being widely used for more than 20 years,LCD technology still has strong vitality,and LCD still accounts for more than 90%of the current screen sales market share.The size of LCD is increasing,the display mode is constantly innovating,and the screen performance is also improving,including higher and higher parameters such as resolution,contrast,brightness and refresh rate.Despite these advances,the development of liquid crystal display devices still encounters a bottleneck.The flat plate structure with hard glass as the substrate cannot be bent,which limits the application of liquid crystal display devices in scenes requiring curved surface display and the free play of creative inspiration of product designers.The flexible liquid crystal display using plastic substrate has the advantages of easy design,light weight and not easy to break,and can realize value in different use scenarios.Therefore,flexible liquid crystal displays are attracting great interest in new application fields,including curved automotive displays,large digital signs,high contrast scrollable TVs and wearable devices.However,there are some problems in the application of liquid crystal materials to flexible devices.Flexible display requires higher production technology.How to ensure the uniform thickness of liquid crystal layer and the neat arrangement and alignment of liquid crystal molecules in display devices is still an urgent problem to be solved.The main work of this paper is to study the mixed alignment layer made of vanadium dioxide(VO₂)nanoparticles and silver(Ag)nanoparticles doped with PI alignment agent,and to study the transmittance,thickness,surface morphology and the distribution of nano particle agglomerates in the alignment layer.The liquid crystal cell is made of mixed alignment layer.The orientation effects under different mixed alignment layers are studied,including anchoring energy,pretilt angle and orientation effect of cells.The threshold voltage and response time of cells are measured.The hybrid alignment layer is applied to the flexible display devices,and the flexible plastic substrate is used to replace the hard glass substrate to prepare the nano particle doped hybrid alignment layer,which is applied to the flexible liquid crystal display device.The alignment effect and photoelectric performance of the flexible liquid crystal cell under different bending conditions are studied.The mixed alignment layer is made by doping VO₂nanoparticles or Ag nanoparticles with PI alignment agent.The thickness of the alignment layer is basically the same as that of the undoped layer,the light transmittance is maintained well under the condition of low doping concentration,and the working voltage of the liquid crystal cell can be well reduced.When the hybrid alignment layer is applied to the flexible liquid crystal display device,it can be found that the hybrid alignment layer can effectively suppress the light leakage caused by the increase of the curvature of the liquid crystal cell,and ensure the alignment effect of the liquid crystal in the bending state.Compared with the flexible devices without bending,the driving voltage and response time of the flexible devices with different curvature only fluctuate in a very small range,which proves the feasibility of using metal or metal oxide nanoparticles doped pi to prepare hybrid alignment layer for flexible liquid crystal display.