Preparation And Production Process Of CdSe/ZnS Quantum Dot Fluorescent Film

The use of different packaging methods for quantum dot materials as a backlight for liquid crystal displays is an important application of quantum dot materials in the display field.However,due to current technical means,quantum dot packaging technology suitable for mass production is still immature.The packaging technology using structure of "on-surface" still faces the disadvantages of unsatisfactory brightness enhancement and long-term stability.The main factors affecting the optical properties of quantum dot films are quantum dot materials and diffusion films,while the quality of the final mass-produced quantum dot film depends on the production process.Therefore,based on the above points,this paper studies the laboratory preparation and production process of CdSe/ZnS quantum dot fluorescent film.The specific work is as follows:(1)The effect of quantum dot glue concentration on the fluorescence characteristics of quantum dot films and the effect of different mass fractions of TiO2 particles in PS on the properties of the prepared diffusion membrane were investigated.l)Different concentrations of quantum dot glue were applied to the PMMA surface,and the fluorescence test showed that the fluorescence intensity reached the strongest when the quantum dot glue concentration was 30 mg/ml.Moreover,as the concentration of the quantum dot glue increased,the fluorescence peak would produce a red-shift phenomenon.2)The TiO2 doped with different mass fractions in PS were coated on the surface of PMMA to form a diffusion film.As the TiO2 increased,the haze of PMMA increased gradually.However,when the TiO2 doping fraction exceeded 4%,the adhesion of the PMMA surface would be significantly reduced.3)Preparation of quantum dot fluorescent film.Fluorescence spectroscopy showed that the CdSe/ZnS quantum dot green light luminescence peak was around 522.5 nm and the FWHM was 34.5 nm.The CdSe/ZnS quantum dot red light was concentrated at about 624 nm,and the FWHM was 34.6 nm.The water vapor transmission rate was between 0.03-0.055 g/m/day,which had good barrier properties.(2)The effect of the thickness of TiO2 and Si3N4 on the properties of PMMA diffusion film was studied and the effect of prism structure on the properties of PMMA diffusion film was investigated.l)Different thicknesses of TiO2 and Si3N4 were separately evaporated on the PMMA surface.Tests have shown that as the thickness of TiO2 increases,the transmittance of the PMMA diffusion film increases;and as the thickness of the Si3N4 layer increases,it helps to improve the adhesion and water vapor transmission rate of the PMMA diffusion film.The vapor deposition of TiO2 and Si3N4 on the PMMA surface by means of an interactive stack enabled the transmittance of the PMMA diffusion film to reach 90%,which reduced the water vapor transmission rate to less than 0.01 g/m2/day.2)The prism structure was prepared on PMMA.The test showed that the brightness enhancement ability was the strongest when the apex angle was 90 degrees.When the structure width reached 50 μm,the PMMA transmittance was the highest.(3)The production process of the quantum dot film is improved.In order to ensure the yield and the optical properties of the final product,a quantum dot film is produced by a sandwich structure one-time film forming process,and the final thickness can be effectively controlled within a certain range by using a precision coating method.The thickness of the quantum dot fluorescent film is between 300 μm and 310 μm,so it can be judged that the overall thickness of the fluorescent film is relatively uniform.