Preparation method of blue light and near ultraviolet excitation type one-dimensional red nano fluorescent powder

Abstract

The invention provides a preparation method of blue light and near ultraviolet excitation type one-dimensional red nano fluorescent powder, belonging to the technical field of luminous material preparation. The method comprises the following steps of: preparing all raw materials according to the molar ratio of the components determined by the chemical general formula of red nano fluorescent powder Ca(1-z)RwOu:zEu<3+> or MyCa(1-x-y)RwOu:xEu<3+>, wherein R is at least one of Ge and Si, and M in an M source is at least one of Li, Na, K, Sr, Mg and Al; adding water into the raw materials and performing ultrasonic treatment for 30-60 minutes; transferring the product into a reaction kettle, and controlling the filling degree of the reaction kettle to be 60-85%; preserving heat at 100-200 DEG C for 1-48 hours; cooling and filtering; and drying the filter residue at 60-90 DEG C to obtain one-dimensional red nano fluorescent powder. The method provided by the invention has the advantages of simple preparation technology, safety and controllability, low preparation temperature, low energy consumption and uniform distribution of the components, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a preparation method of a blue-light and near-ultraviolet-excited one-dimensional red nano-fluorescent powder, belonging to the technical field of luminescent material preparation. Background technique [0002] Solid-state lighting is a technology that uses semiconductor light-emitting diodes (LEDs) to manufacture lighting sources. It has significant advantages such as green environmental protection, good weather resistance, high theoretical light efficiency, energy saving, long life, rich colors, fast response, easy miniaturization and maintenance-free. , so it is known as a new generation of light sources after incandescent lamps, fluorescent lamps and energy-saving lamps. It is expected to replace traditional lighting sources and has very broad application prospects. Based on the current development of LED technology and production costs, the way to obtain white LEDs is mainly to use near-ultraviolet or blue LED single-chips...

AI Technical Summary

Problems solved by technology

Compared with blue and green phosphors, Y 2 o 2 S:Eu 3+ There are the following outstanding shortcomings: expensive; can not effectively absorb excitation light around 400nm; emit sulfide gas under ultraviolet light irradiation, pollute the environment, resulting in unstable chemical properties and shortened service life; and the phosphor powder of the aluminate system has moisture resistance Poor, single luminous color and other disadvantages, and the cost is high, and the synthesis conditions are relatively harsh; the luminous intensity of molybdate system phosphors is weak, which limits its application range to a large extent

A large number of defects in nanomaterials can form energy transfer with active center ions, so that energy transfer between nanomatrix and active center ions can make it contribute to the luminescence of phosphors. Therefore, by integrating nanomatrixes, especially one-dimensional nanomatrixes and The excellent optical properties of both rare earth ions can further improve the luminescent properties of phosphors, which cannot be achieved in micron-scale matrix phosphors prepared by traditional methods (such as high-temperature solid-phase method)

At present, the research on nano-matrix phosphors is mainly focused on nanoparticles. The research has observed that the luminous efficiency is improved, the fluorescence is enhanced, and the quenching concentration of rare earth ions in nanocrystals is higher than that of bulk materials, but it is also found that there is no radiation. The transition is significantly improved, resulting in a decrease in quantum efficiency

The main reason is that nanoparticles are a three-dimensional restricted system, and it is difficult to effectively control a large number of surface defects on the surface. These surface defects, while becoming radiation centers, also serve as channels for non-radiative transitions, improving nano Nonradiative transition rates of particles, reducing electronic transition rates and quantum efficiencies of rare earth ions in zero-dimensional nanoparticles

[0005] Traditional red phosphors generally use high-temperature solid-phase method, which has low doping concentration, poor doping uniformity and particle size uniformity, high sintering temperature, high energy consumption, many processes, high cost, and difficulty in forming nanoscale matrix, etc. defect

The preparation of micro / nano-particle three-color phosphors generally adopts the sol-gel method, although the sol-gel method has: (a) low operating temperature; (b) easy to accurately control the doping amount; (c) can avoid the experimental The introduction of impurities maintains the purity of the sample; (d) the precursor solution is mixed at low temperature and can achieve a high degree of uniformity at the molecular level, but there are also the following disadvantages: (a) the entire sol-gel process requires It takes a long time and often takes several days or weeks; (b) the final product still needs a calcination process to obtain, which increases the production cycle and cost; (c) there are a large number of micropores in the gel, and the calcined Many gases and harmful gases such as organic matter will escape, and shrinkage and agglomeration will occur. After calcination, the particles will grow up and the sintering performance will be poor.

The hydrothermal method is a new method developed in recent years for the preparation of one-dimensional nanomaterials. It has: (a) easy operation; (b) sufficient conversion of raw materials; (c) can form a special high temperature and high pressure environment, making it difficult to The characteristics of soluble or insoluble substances are dissolved and recrystallized. By controlling the molar ratio of raw materials, reaction temperature, reaction time and filling degree, it is very convenient to synthesize large-scale one-dimensional nanomaterials with uniform diameter distribution. However, hydrothermal There are relatively few studies on the preparation of phosphors by the hydrothermal method, mainly because the temperature of the hydrothermal method is relatively high, the requirements for equipment are relatively high, the technology is difficult, and the safety performance is poor.

[0006] At present, there is no report on the preparation of one-dimensional nano-phosphor powder by sol-hydrothermal method

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