Abstract: The present invention is a single-component, UV-emitting phosphor having a composition represented by the general formula (Y1?x?y?zLaxGdyCeZ)PO4 where x has a value in a range from 0.001 to 0.98, y has a value in a range from 0 and 0.1, z has a value in a range from 0.01 and 0.2, and x+y+z<1. The phosphor when stimulated by 254 nm radiation emits in both the UVA and UVB regions. The relative balance of the UVA and UVB emissions may be varied by adjusting the relative amounts of Y and La. Brightness can be increased by adding Gd to the composition.

Abstract: A process for preparing particles of zinc sulfide-based electroluminescent phosphor having a moisture resistant coating thereon which comprises the steps of selecting a reaction vessel having a given height and a porous disc at the bottom thereof; charging the reaction vessel with phosphor particles and fluidizing the particles by introducing an inert gas into the vessel through the porous disc; heating the reaction vessel to a reaction temperature; introducing a coating precursor into the reaction vessel at a position adjacent the bottom of the vessel but above the disc; introducing a co-reactant into the reaction vessel at a position substantially mid-way of the given height; and maintaining the inert gas flow, the precursor flow and the co-reactant flow for a time sufficient for a reaction to occur and coat the phosphor with the moisture resistant coating. Apparatus for carrying out the process is also disclosed.

Abstract: A process for making an electroluminescent phosphor having a given emission spectra A, comprises the steps of manufacturing a beginning electroluminescent phosphor having an emission spectra B, different than A. A coating is applied to the phosphor having the emission spectra B to increase the resistance of the phosphor to the deleterious effects of moisture and change the emission spectra of the phosphor to emission spectra A. The application of the coating includes the steps of reacting a coating precursor with a mixture of oxygen and ozone.

Abstract: A process for preparing particles of zinc sulfide-based electroluminescent phosphor having a moisture resistant coating thereon which comprises the steps of selecting a reaction vessel having a given height and a porous disc at the bottom thereof; charging the reaction vessel with phosphor particles and fluidizing the particles by introducing an inert gas into the vessel through the porous disc; heating the reaction vessel to a reaction temperature; introducing a coating precursor into the reaction vessel at a position adjacent the bottom of the vessel but above the disc; introducing a co-reactant into the reaction vessel at a position substantially mid-way of the given height; and maintaining the inert gas flow, the precursor flow and the co-reactant flow for a time sufficient for a reaction to occur and coat the phosphor with the moisture resistant coating. Apparatus for carrying out the process is also disclosed.

Abstract: A process for preparing particles of zinc sulfide-based electroluminescent phosphor having a moisture resistant coating thereon which comprises the steps of selecting a reaction vessel having a given height and a porous disc at the bottom thereof; charging the reaction vessel with phosphor particles and fluidizing the particles by introducing an inert gas into the vessel through the porous disc; heating the reaction vessel to a reaction temperature; introducing a coating precursor into the reaction vessel at a position adjacent the bottom of the vessel but above the disc; introducing a co-reactant into the reaction vessel at a position substantially mid-way of the given height; and maintaining the inert gas flow, the precursor flow and the co-reactant flow for a time sufficient for a reaction to occur and coat the phosphor with the moisture resistant coating. Apparatus for carrying out the process is also disclosed.

Abstract: A long-life, white-emitting phosphor blend is provided which comprises about 75 wt. % of a first electroluminescent phosphor having an x color coordinate of about 0.530 and a y color coordinate of about 0.455; about 10 wt. % of a second electroluminescent phosphor having an x color coordinate of about 0.185 and a y color coordinate of about 0.440, said second electroluminescent phosphor containing about 600 ppm copper; and about 15 wt. % of a third electroluminescent phosphor having an x color coordinate of about 0.160 and a y color coordinate of about 0.175, said third electroluminescent phosphor containing about 300 ppm copper.

Abstract: A method of coating phosphor particles comprises introducing an inert gas into a reaction vessel and charging phosphor particles into the reaction vessel. The reaction vessel is then heated to a reaction temperature and a coating precursor is introduced while the temperature is maintained for a time sufficient to saturate the phosphor particles with the precursor. Thereafter, continuous precursor is introduced into the reaction vessel, along with an oxygen/ozone mixture. The inert gas flow, oxygen/ozone mixture flow and further precursor are supplied for a time sufficient to coat the phosphor particles.

Abstract: An orange-yellow-emitting zinc sulfide-based electroluminescent phosphor is described wherein the phosphor has a brightness of greater than 10 foot-Lamberts. More particularly, the phosphor has a brightness of at least about 13 foot-Lamberts and an x color coordinate from about 0.51 to about 0.56 and a y color coordinate from about 0.42 to about 0.48. The zinc sulfide phosphor is activated with manganese, copper, chlorine, and a metal selected from gold and antimony.

Abstract: A long-life, white-emitting phosphor blend is provided which comprises about 75 wt. % of a first electroluminescent phosphor having an x color coordinate of about 0.530 and a y color coordinate of about 0.455; about 10 wt. % of a second electroluminescent phosphor having an x color coordinate of about 0.185 and a y color coordinate of about 0.440, said second electroluminescent phosphor containing about 600 ppm copper; and about 15 wt. % of a third electroluminescent phosphor having an x color coordinate of about 0.160 and a y color coordinate of about 0.175, said third electroluminescent phosphor containing about 300 ppm copper.

Abstract: A method of recovering a base phosphor from encapsulated phosphors, which comprises the steps of selecting a recovery vessel including a magnetic stir bar; adding to the recovery vessel, deionized water, a first batch of concentrated hydrochloric acid and encapsulated phosphor to form a stirred suspension; heating the stirred suspension to about 90° C. for about 2 hours; settling the stirred suspension; decanting the mother liquor and slurrying the remaining solids with a second batch of hydrochloric acid and water; decanting and washing the remaining solids with deionized water; filtering the remaining solids to form a filter cake; heating the filter cake at 110° C. in air for a time sufficient to form a dried filter cake; and screening the dried filter cake through a −325 mesh screen to yield a recovered base phosphor.

Abstract: A long-life, high-brightness, moisture-resistant electroluminescent phosphor comprising a base phosphor having the general formula ZnS;Qu,Cl,Au and having a moisture-resistant coating thereon, said coating being selected from the group consisting of a metal nitrides or metal oxide/hydroxides.

Abstract: A method of recovering a base phosphor from encapsulated phosphors, which comprises the steps of selecting a recovery vessel including a magnetic stir bar; adding to the recovery vessel, deionized water, a first batch of concentrated hydrochloric acid and encapsulated phosphor to form a stirred suspension; heating the stirred suspension to about 90° C. for about 2 hours; settling the stirred suspension; decanting the mother liquor and slurrying the remaining solids with a second batch of hydrochloric acid and water; decanting and washing the remaining solids with deionized water; filtering the remaining solids to form a filter cake; heating the filter cake at 110° C. in air for a time sufficient to form a dried filter cake; and screening the dried filter cake through a −325 mesh screen to yield a recovered base phosphor.

Abstract: A method of coating phosphor particles by chemical vapor deposition. The phosphors are coated by 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 coating precursor which includes carbon into the reaction vessel for a time sufficient to saturate the phosphor particles with the precursor; continuing precursor flow into the reaction vessel; introducing an oxygen/ozone mixture into the reaction vessel, the oxygen/ozone mixture comprising less than 4.4 wt. % ozone; and maintaining the inert gas flow, oxygen/ozone mixture flow and further precursor supply for a time sufficient to coat the phosphor particles. The process produces phosphors having from 2200 to 6300 ppm of carbon on the coating and provides lamp efficacy's of greater than 6.1 lm/watt.

Abstract: A process for preparing particles of zinc sulfide-based electroluminescent phosphor having a moisture resistant coating thereon which comprises the steps of selecting a reaction vessel having a given height and a porous disc at the bottom thereof; charging the reaction vessel with phosphor particles and fluidizing the particles by introducing an inert gas into the vessel through the porous disc; heating the reaction vessel to a reaction temperature; introducing a coating precursor into the reaction vessel at a position adjacent the bottom of the vessel but above the disc; introducing a co-reactant into the reaction vessel at a position substantially mid-way of the given height; and maintaining the inert gas flow, the precursor flow and the co-reactant flow for a time sufficient for a reaction to occur and coat the phosphor with the moisture resistant coating. Apparatus for carrying out the process is also disclosed.

Abstract: 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 nitride coating precursor into the reaction vessel in a manner to avoid restrictive reactions; introducing a co-reactant into the reaction vessel; and maintaining the inert gas flow, co-reactant flow and precursor supply for a time sufficient to moisture-proof the phosphor particles.

Abstract: A method of coating phosphor particles by chemical vapor deposition. The phosphors are coated by 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 coating precursor which includes carbon into the reaction vessel for a time sufficient to saturate the phosphor particles with the precursor; continuing precursor flow into the reaction vessel; introducing an oxygen/ozone mixture into the reaction vessel, the oxygen/ozone mixture comprising less than 4.4 wt. % ozone; and maintaining the inert gas flow, oxygen/ozone mixture flow and further precursor supply for a time sufficient to coat the phosphor particles. The process produces phosphors having from 2200 to 6300 ppm of carbon on the coating and provides lamp efficacy's of greater than 6.1 lm/watt.

Abstract: A method of coating phosphor particles that 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 coating precursor into the reaction vessel; introducing an oxygen/ozone mixture into the reaction vessel; and maintaining the agitation, inert gas flow, oxygen/ozone mixture flow and precursor supply for a time sufficient to coat the phosphor particles. This process yields phosphors having a half-life of upwards of 3,100 hours with efficacys of greater than 6 lumens per watt (lm/w).

Abstract: 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 nitride coating precursor into the reaction vessel in a manner to avoid restrictive reactions; introducing a co-reactant into the reaction vessel; and maintaining the inert gas flow, co-reactant flow and precursor supply for a time sufficient to moisture-proof the phosphor particles.

Abstract: A method for forming a continuous, conformal non-particulate coating of boron oxide on individual phosphor particles is provided. The method involves reacting a boron-containing precursor with an oxidizing gas in a fluidized bed of phosphor particles. The boron oxide coated phosphor exhibits an increased quantum efficiency under ultraviolet (UV) and vacuum ultraviolet (VUV) excitation.