YAGG:Tb phosphor is very excellent in its brightness

especially in the projection TV it shows good application foreground.The particle size of phosphor has compact relation with definition of image

the smaller the particle size is

the higher the definition is. Nano phosphor can improve the definition and give us more clear picture. The preparation of YAGG:Tb nano phosphor is introduced

the way of preparation is urea-sol method

it has some merits than other methods.This method is inorganic way

we can acquire nano phosphor.The particle-size and shapes of different temperature superfine-particle phosphors are observed and taken photos with scanning electron microscopy (SEM).The diffraction patterns of them are measured by X-ray diffractometer (XRD).In the end

we discuss the experiment result.The experiment of urea-sol method for synthesizing global

well-proportioned

super fine-particle YAGG:Tb green phosphor whose particle-diameter is 80~300 nm is discussed in detail. The particle-size and shapes of superfine-particle phosphors prepared at different temperature are observed in the photos taken by scanning electron microscopy.We found that the particle is bigger at the higher temperature and the phenomenon of conglomerating appears.The way of surface coating is adopted to solve the conglomerating problem. The diffraction patterns of them are measured by X-ray diffractometer (XRD) and the microcrystalline-structure is analyzed. We may draw a conclusion the that particle we prepared is YAGG:Tb. A comparison in luminance is given between superfine-particle phosphor and Japanese commercial projection-tube phosphor. So the characteristics of luminance should deeply and carefully promoted in many aspects.