Application Research On Quantum Dot Color Converter

This thesis mainly studied a color converter film using quantum dots as wavelength convension materials,and explores its composition material,manufacturing method and application.The film can be applied to the upper layer of display backboard of liquid crystal display to replace color filter,also can realize color conversion for micro-LED display devices.By using quantum dot color converter,the backlight utilization rate of LCD can be improved so the backlight energy can be saved,at the same time can also improve the purity of color,broaden the color gamut.By comparing several mature techniques for making quantum dot color converter,this paper decides to use photolithography.By comparing different types of photoresists and red and green quantum dot,the photo-chemical reactions of different types of photoresists and the degree of quenching damage to quantum dot were analyzed,then the photoresist and quantum dot to be used in this study were reasonably selected.At the same time,the influence of each step in photolithography process of film-forming property of quantum dot color converter was studied,the parameters and conditions of photolithography which are specially designed for the mixed and dispersed photoresist with quantum dots are designed to minimize the influence of the photochemical reaction and baking development on quantum dot,also,the suitable concentration ratio conditions of the mixture of quantum dot and photoresist are summarized.Further,by using a carboxyl glutarate group present at both ends to modify the surface ligands of quantum dot,the problem of poor dispersion of original CDSe/CdZnS quantum dot,photoresist and their solvents can be improved,so as to increase solubility of quantum dot and photoresist.The average thickness of the film is between 4-4.5 um,and quantum yield of red quantum dot color converter can reach over 70%,the optical density is above 2.The quantum yield of green quantum dot color converter is between 50% and 60%,and the optical density can reach about 0.8.