A new application for microgels: Novel method for the synthesis of spherical particles of the Y2O3 : Eu phosphor using a copolymer microgel of NIPAM and acrylic acid

The preparation of spherical phosphor europium-doped yttrium oxide (Y2O3:Eu ) particles using a copolymer of N-isopropylacrylamide (NIPAM)] and acrylic acid (AAc) is described. The resulting phosphor particles have smaller par ticle diameters (<0.1 mum) compared to both commercial Y2O3:Eu phosphors an d spherical particles synthesized by the urea precipitation method. Cathodo luminescent (CL) measurements demonstrate that exceptional light output is achieved from the smaller particle diameters than 0.1 mum. The luminescent properties of the phosphors synthesized via the copolymer microgel are show n to be at least comparable to commercial products at lower voltages; howev er, they offer the distinct advantage of a higher packing density and there fore higher resolution for field emissive displays (FED's) and cathode ray tube (CRT) applications.