Preparation And Performance Of Light Guide Plate Based On Perovskite Nanostructure

Liquid crystal display（LCD）is one of the most proven display devices at present.However,with the improvement of people life quality,the color gamut of the traditional LCD cannot meet people requirements.The improvement of the color purity and uniformity of the LCD backlight is a problem that needs to be solved urgently.Perovskite has been developed rapidly in recent years due to its high luminous performance,especially in optical film integrated backlight structures.In order to improve the color and the brightness performance of the LCD backlight,the perovskite material are combined with the microstructure-type light guide plate（LGP）.In this article,the detailed research is carried out from the following aspects:the synthesis of perovskite nanomaterials,configuration of LGP printing paste,and the photoluminescence characteristics and stability of the LGP.Firstly,the synthesis and solvent compatibility of perovskite quantum dots（QDs）were studied.Perovskite QDs were prepared by the ligand assisted reprecipitation method and the high temperature thermal injection method.Among them,the oleic acid/oleylamine ligand modified QDs have a uniform particle size and higher color purity of the emission spectrum,which was obtained by the high temperature thermal injection method.Furthermore,the compatibility of the dissolved solution was studied to obtain a QDs solution with better dispersion effect,which can maintain the stability of the QDs and avoid agglomeration quenching.Secondly,the LGP based on perovskite QDs was prepared by the screen printing.The solubility of printing paste and different perovskite QDs solutions was studied.After mixing,the printing paste was spin coated into a film,and then the fluorescence spectrum was analyzed to obtain the printing paste with the best solubility.Furthermore,through adjusting the ratio of red（Cd Se）to green（Cs Pb Br₃）QDs in the paste,the perovskite QDs monochrome and mixed-color LGP were prepared.Finally,the microstructure morphology and light-emitting effect were characterized,and the LGP based on perovskite QDs with high color gamut and brightness uniformity was obtained.Then,UV glue was used to improve the stability of LGP by overprinting light guide microstructure.It was found that the fluorescence intensity of QDs decreases under different water and oxygen conditions,indicating that fluorescence quenching still exists inside the microstructure of QDs.To solve this problem,UV glue was overprinted to encapsulate the light guide microstructure.The morphology of QDs microstructure and LGP light-emitting effect with different encapsulation times were characterized.The interval brightness and continuous lighting aging tests of LGPs with different overprint times were carried out,which verifies that overprint encapsulation method can effectively improve the stability of LGPs.Finally,through improving the stability of the material itself,the stability of the perovskite LGP was further improved.The perovskite nanocrystals were synthesized by thermal injection of benzoyl bromide and the microstructure LGP based on perovskite nanocrystals was prepared.The particle size,structure and fluorescence spectrum of the perovskite nanocrystals were characterized,with the microstructure morphology and the light-emitting effect of the perovskite nanocrystals LGP were tested.The brightness decay rate of interval lighting and continuous lighting was further tested,and compared with the LGP based on perovskite QDs.The experimental results indicate that the LGP based on perovskite nanocrystals has higher brightness stability,and the oil-based ammonium ion passivates the surface of the perovskite nanocrystals.The application of perovskite nanocrystals in the microstructure of LGP,not only can effectively improve the brightness and color expression,but also maintain the stability of the LGP.