Manufacturing methods and GaN phosphor of GaN phosphor

摘要

PROBLEM TO BE SOLVED: To produce a GaN fluorescent substance having good crystallinity and lighter coloration, containing additives homogeneously added thereto in good controllability, and having a large emission intensity. ;SOLUTION: Gallium nitrate hydrate [Ga(NO3).8H2O] is mixed with 1 mol% solution of zinc nitrate, and ammonia is added dropwise to the obtained mixture to provide a gallium hydroxide with coprecipitated Zn. The coprecipitated hydroxide is reacted in an ammonia atmosphere at 1,100°C for 3 hr to provide GaN:Zn fluorescent substance. The substance has nearly white color without grayish black or yellow coloring. The reflectivity of the light in a blue wave length of 450 nm is 75%, and the reflectivity of a conventional fluorescent substance obtained by using a sulfide (Ga2S3) as a raw material is lower than this reflectivity. The fluorescent substance is a spherical crystal having 0.3-2.0 μm diameter even though the conventional GaN fluorescent substance is a needle crystal. The fluorescent substance provides a broad emission spectrum having a peak at 440 nm when the substance is allowed to emit the light by a mercury-vapor lamp.;COPYRIGHT: (C)2000,JPO