Preparation Of Small Size LED Phosphor By High Gravity Method And Its Application

LED lighting,as the most advantageous and efficient energy-saving lighting technology,has become a key promotion product of countries all over the world.Phosphor is a key material for white LED lighting devices,and its composition,size,morphology and emission wavelength have an important impact on the performance of LED packaged devices.The traditional preparation of phosphor is solid-state burning method,and the particle size is in the micron level with wide distribution,which seriously affects the stability of the LED package device.Phosphor powder materials for LEDs are usually micro-nano oxides and compounds particles doped with luminescent ions.According to product engineering principle,the preparation of phosphor requires a narrow size distribution of the matrix particles,while doping ions concentration in the matrix particles is uniform to ensure stable product quality and consistent performance.The key scientific issue involved is how to effectively control the mesoscale structure of phosphor in the material preparation process.This topic proposes a new idea to strengthen the preparation of small-sized LED phosphors by high-gravity,and successfully prepared two types of phosphor materials:GdBO3:Eu3+and Zn2GeO4:Mn2+.For the preparation of GdBO3:Eu3+phosphor material,the uniform precipitation of matrix material and Eu3+ in the urea solution is strengthened by the high-gravity technology,and then use the high-temperature annealing method to prepare the sample.Under the excitation of 395 nm ultraviolet light,the material can emit bright red light,with an emission peak at 625 nm,the chromaticity coordinate is(0.598,0.341),the quantum yield is 78.11%,and it has good thermal stability performance at 423 K.Applying this phosphor material to LED package devices,it performance well.For the preparation of Zn2GeO4:Mn2 phosphor material,the molecular mixing and mass transfer of the liquid phase reaction crystallization process is strengthened by high-gravity technology,which effectively control the explosive uniform nucleation of the reaction precursor,and further use the hydrothermal crystallization to prepare small-sized nano-rod materials.The samples are rod-shaped particles with regular morphology and good dispersibility in the range of 200-300 nm,which exhibit green light with an emission peak at 535 nm under the excitation of 254 nm deep ultraviolet light.As the same time,this subject explores the process conditions for the preparation of Zn2GeO4:Mn2+phosphor by high-gravity.As a special transition metal element,Mn element is expected to solve the problem of excessive amount of rare earth in the existing phosphor material.