| With the advent of the information age,the development of optoelectronic display technology has made rapid progress,and the preparation of display devices with excellent performance has gradually become the focus of research in the field of information display.Since the development of liquid crystal display,it has become the most widely used display device in people's life and work,occupying the mainstream of the display market for a long time.In recent years,electronic devices have been iteratively updated at an ultra-fast speed,and smart devices have higher and higher requirements for liquid crystal displays.Liquid crystal display devices are usually used in large-scale display devices.Slow response speed and high energy consumption have gradually become one of the key technical factors restricting their development.It is one of the urgent problems to be solved in the display field.During the development of nanoscience and technology,many new nanomaterials have been born,especially some two-dimensional nanomaterials have shown extremely high application value in the field of optoelectronic devices.In this paper,two-dimensional nano-flakes of molybdenum disulfide(Mo S2)and MXene were doped into polyimide(PI)alignment agent to prepare a hybrid alignment layer,and the thickness,light transmittance,surface energy,surface morphology and dispersion of nano-flakes on the surface of the alignment layer were studies.The liquid crystal cell was assembled with the hybrid alignment layer,its alignment effect was studied,and the threshold voltage and response time of the liquid crystal cell were tested.The hybrid alignment layer was applied to the photo-erasable liquid crystal device,and its alignment effect was studied and the threshold voltage,response time and optically rewritable time of the optically rewritable liquid crystal cell were tested.The main research conclusions are as follows:(1)Mo S2 nano-flakes agglomerates could be observed on the surface of the Mo S2/PI hybrid alignment layer,and the coverage area of the agglomerates increased significantly with the increase of Mo S2 concentration.Mo S2 nano-flakes reduced the light transmittance of the alignment layer in the visible light wavelength range,but it remained above 85%.Doping Mo S2 changed the surface properties of the alignment layer to a certain extent.The dispersion of Mo S2 in the alignment layer made the surface roughness of the layer increase,the thickness increase,and the solid surface energy decrease.The liquid crystal cell prepared with Mo S2/PI hybrid alignment layer,the experiment showed that the alignment effect of the liquid crystal cell sample was remarkable,and there was only a weak light leakage phenomenon when the doping concentration was 1%.When the doping concentration was 1%,compared with the liquid crystal cell of pure PI alignment layer,the threshold voltage was reduced by 37.24%,and the response time was only 47.90%of that of pure PI.The hybrid alignment layer was applied to the preparation of optically rewritable liquid crystal devices,and the threshold voltage,response time and optically rewritable time of the rewritable liquid crystal cell were measured.The decrease in response time was 25.18%,and the optically rewritable time was only 46.41%of the pure PI liquid crystal cell.(2)MXene/PI hybrid alignment layers were prepared and characterized.The scanning electron microscope image of the hybrid alignment layer showed that there were layered agglomerates on its surface,and the coverage area of MXene on the surface of the alignment layer increased with the increase of doping concentration.MXene changed the viscous force of the PI alignment agent,resulting in a significant increase in the thickness of the alignment layer.MXene nano-flakes significantly changed the surface undulation,roughness and thickness of the alignment layer,but the light transmittance was always above 88%.MXene increased the contact angle between the alignment layer and the detection liquid to a certain extent,and reduced the solid surface energy of the alignment layer.The alignment effect and optical-electrical properties of the liquid crystal cell prepared by MXene/PI hybrid alignment layer were analyzed.The alignment effect of the liquid crystal cell sample was remarkable.When the MXene doping concentration increased,a small amount of light leakage in the dark state was observed by polarizing microscope.When the doping concentration was 0.5%,the threshold voltage was reduced by 13.02%compared with the liquid crystal cell of pure PI alignment layer,and the total response time was 54.32%of that of the pure PI liquid crystal cell.When the doping concentration was 0.5%,the threshold voltage of the optically rewritable liquid crystal cell decreases by as much as 20.85%,and the response time increased slightly.The rewritable time was 42.95s,which was 26.77s shorter than that of pure PI,and the decrease was 38.40%.In summary,doping Mo S2 and MXene in the alignment layer is a simple and effective way to reduce the driving voltage of liquid crystal display devices and improve the response speed under the action of electric field,which can be applied in the preparation of low-voltage driving and fast-response liquid crystal display and ultra-fast response optically rewriting liquid crystal display. |
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