摘要 |
A phosphor particle has thereon a moisture resistant treatment of a metallic nitride. By moisture resistant is meant a condition allowing the phosphor particle to function in a humid atmosphere for a significantly longer period of time than an untreated particle. The method of making such phosphors comprises the steps of introducing an inert gas into a reaction vessel; charging phosphor particles into the reaction vessel; heating the reaction vessel to a reaction temperature. introducing a first precursor compound such as triiosbutyl aluminum and a second precursor compound such as dimetylamine into a second reaction vessel to form a nitride precursor. The nitride precursor is hexakis(dimethylamido)dialuminum. The nitride precursor is introduced into the first reaction vessel in a manner to avoid restrictive reactions. A a co-reactant is introduced into the reaction vessel, the inert gas flow, co-reactant flow and precursor supply are mainitained for a time sufficient to make the phosphor particles moisture resistant. The nitride treated phosphor particles produced by this method, which can include the deposition of a nitride coating on the particles, have excellent efficacy ratings and strong luminance values in lamps after 100 hours use in high humidity (i.e., >95%). By avoiding restrictive reactions and by synthesizing the nitride precursor on stream, the method and apparatus can be used to manufacture commercial quantities of coated phosphors at an economical cost.
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