Preparation,Property Modulation And Optical Application Of Carbon Dots Fluorescent Powders

High-efficiency fluorescent carbon dots,as the new generation nano-fluorescent material,have been widely used in luminescent devices,fingerprint verification,and biological detection,due to its low-cost,easy-gained,excellent fluorescence ability,and outstanding chemical properties.However,carbon dots tend to be aggregated together in solid-state,which leads to fluorescence quenching and hinders the application of carbon dots as fluorescent materials.We explore the mechanism of C-dots luminescence,the problem of agglomeration quenching of C-dots was alleviated by anchoring of matrix material,and the C-dot phosphors with high luminous efficiency was prepared.Then,a C-dots energy level model is constructed to analyze the luminescence mechanism,and290nm deep ultraviolet phosphors are prepared.C-dots phosphorescent phosphors are obtained based on C-dots luminescence mechanism and white light emitting diode?WLED?is prepared.The main research contents and conclusions are as follows:1.Using amorphous silica or zinc oxide as a disperse mechanism of carbon dots,3-aminopropyltriethoxysilane as silicon source,C-dots@SiO₂ phosphor is prepared by hydrothermal method.The fluorescence wavelength?450 nm-580 nm?regulation of the complex is realized by adjusting the amount of o-phenylenediamine.A light-emitting model of the complex was constructed by introducing m-phenylenediamine and p-phenylenediamine and we prove that the far-ultraviolet luminescence of carbon dots originated from the sp² carbon structure of the core of carbon dots and visible fluorescence of carbon dots originates from functional groups and carbon structure on the surface of carbon dots.White LED device with color coordinate?0.326,0.330?is prepared by using this phosphor.Moreover,the far ultraviolet light-emitting devices are constructed.And the application of the phosphor in fingerprint verification is systematically investigated.The results show that the carbon dots phosphor has excellent performance in the field of luminescent devices and fingerprint verification,which has broad application prospect.2.The white luminescence phosphors of C-dots@ZnO are prepared,and we found that it have phosphorescence.By adjusting the concentration of C-dots in the reaction precursor and the temperature of the preparation process,the fluorescence properties and the luminescence mechanism of the phosphors are analyzed.It is proved that the interaction between the surface functional groups of carbon dots and the lattice of zinc oxide can stimulate the phosphorescence of carbon dots.In addition,based on this phosphors,the White LED device with color coordinate?0.280,0.320?is obtained with excellent luminescence performance.3.Carbon dot solution is prepared by hydrothermal method with citric acid and4-alkoxy o-phenylenediamine as precursor reactants.We Characterize the upconversion characteristics of C-dots solution.By introducing o-phenylenediamine and3,4-diaminobenzoic acid,it is concluded that the benzene ring structure of the precursor reactants leads to the 560nm fluorescence peak and the new functional groups introduced affect the fluorescence performance through their interaction.At last the effect mechanism of precursor reactants,pH value of precursor reaction solution and pH value of C-dots solution on the luminescent properties of C-dots solution are analyzed.