Osram Sylvania Inc.

Thomas M Snyder

Gregory A Marking

Chen-Wen Fan

Eric A Thomason

Chen Wen Fan

Shellie K Northrop

Robert T McSweeney

Chung-nin Chau

Eric R Mercer

There is described a method of producing a red-emitting manganese and cerium co-activated gadolinium magnesium zinc pentaborate phosphor that comprises combining a hydrated hexaborate of zinc, magnesium, and manganese with oxides of Gd and Ce to form a mixture, and firing the mixture in a slightly reducing atmosphere to form the phosphor. Preferably, the hydrated hexaborate has an approximate composition represented by (Zn,Mg,Mn)BO.XHO, where X is 5.3 to 6.2.

Method of making red-emitting borate phosphor

A method of producing a UV-emitting magnesium pentaborate phosphor is described. The method comprises combining a hydrated magnesium hexaborate with oxides of Y, Gd, Ce and Pr to form a mixture and firing the mixture in a slightly reducing atmosphere to form the phosphor. The hydrated magnesium hexaborate, which is preferably prepared as a precipitate, preferably has a formula MgBO.XHO where X is from 4 to 6.

Method of producing UV-emitting magnesium pentaborate phosphors

Blue-emitting phosphors for use with plasma display panels (PDP) or other vacuum ultraviolet-excited (VUV) devices are provided. These blue-emitting phosphors and mixtures thereof include at least a europium-activated calcium-substituted barium hexa-aluminate (CBAL) phosphor. Preferably, the CBAL phosphor has a composition which may be represented by the formula: BaCaEuAlO, wherein 0&#x3c;x&#x3c;0.25 and 0.01&#x3c;y&#x3c;0.20. These blue-emitting phosphors exhibit improved degradation characteristics, including reduced color shift and increased intensity maintenance, under conditions found in VUV-excited devices.

VUV-excited device with blue-emitting phosphor

The sensitivity of YPO:Ce phosphors to 185 nm radiation may be increased by incorporating a praseodymium coactivator. The use of Ce and Pr as co-activators in a YPOphosphor improves the sensitivity of the phosphor to excitation by both 185 nm and 254 nm radiation and should increase total UVA and UVB output in fluorescent lamps. The co-activated phosphor has emission peaks at about 355 nm and about 335 nm.

Ce,Pr-coactivated yttrium phosphate phosphor and lamp containing same

A Sr(Al,Mg)O:Ce,Pr phosphor is described wherein the phosphor has an increased sensitivity to excitation by 185 nm radiation compared to a Sr(Al,Mg)O:Ce phosphor. The Ce,Pr-coativated strontium magnesium aluminate phosphor emits ultraviolet (UV) radiation at about 306 nm in the UVB region. Suntan lamps made with this phosphor exhibit improved performance over lamps made with a commercial Sr(Al,Mg)O:Ce phosphor.

Ce,Pr-coactivated strontium magnesium aluminate phosphor and lamp containing same

The UVC emission of a Sr(Al,Mg)O:Pr is improved by providing an excess of magnesium relative to the molar amount praseodymium In particular, the UVC-emitting phosphor has a composition represented by the formula SrPrAlMgOwherein y&#x3e;x. The phosphor is excited by vacuum ultraviolet radiation and may be used to create a mercury-free germicidal lamp.

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A UV-emitting phosphor is described wherein the phosphor is excitable by vacuum ultraviolet radiation (VUV). The phosphor is a gadolinium-activated strontium magnesium aluminate which preferably has an excitation maximum at about 172 nm. The phosphor exhibits a narrow-band UV emission at about 310 nm which makes it useful for medical phototherapy applications.

UV-emitting phosphor and lamp containing same

A UV-emitting phosphor comprising SrBO:Eu phosphor particles that have been treated to yield a surface layer containing from greater than 0 to about 25 atomic percent aluminum. The holdover stability of the treated SrBO:Eu phosphor improves the 100-hour maintenance in a fluorescent tanning lamp to the extent that the treated phosphor may be subject to a holdover period of more than 25 days without a significant change in its 100-hour maintenance.

UV-emitting strontium borate phosphor with improved holdover stability

A method is provided for making narrow-band, UVB-emitting, (Y,Gd,Ce,Pr)Mg borate phosphors. The method involves the use of a mixed oxide co-precipitate which is combined with MgO and boric acid and fired twice to form the borate phosphor. The mixed oxide co-precipitate is formed by dissolving sources of Y, Gd, Ce, and optionally Pr, in an acid solution. Oxalic acid or ammonia is added to the solution (or vice versa) to form a co-precipitate of oxalates or hydroxides that are further fired to obtain a mixed oxide co-precipitate. The use of the mixed oxide co-precipitate improves homogeneity and yields a phosphor having a higher brightness with very little or no sticking between the fired cakes and the firing crucibles.

Method of making narrow-band UVB-emitting phosphors

A method of making a haloapatite phosphor having a general formula represented by (CaMnSb)(PO)(FClO), where 0&#x3c;x&#x3c;0.05, 0.004&#x3c;y&#x3c;0.01, and 0&#x3c;z&#x3c;0.1. is provided. The method involves (a) formulating a blend of ingredients to make the haloapatite phosphor, the ingredients including CaHPOas a primary source of calcium and phosphorus, (b) partially substituting an amount of an equimolar combination of an ammonium phosphate compound and calcium carbonate for an equal number of moles of CaHPOin the formulation, (c) combining the ingredients in their formulated amounts to form the blend, and (d) firing the blend to form the haloapatite phosphor. The partial substitution has been found to increase the 100-hour brightness of the haloapatite phosphors.

Method of making haloapatite phosphors

The present invention is a single-component, UV-emitting phosphor having a composition represented by the general formula (YLaGdCe)POwhere 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&#x3c;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.

Single-component, UV-emitting phosphor

A narrow-band UVB emitting phosphor is described wherein the phosphor has a preferred composition represented by the general formula (YGdCePr)MgBOwhere x has a value in a range from 0.02 to 0.80, y has a value in a range from 0.01 to 0.97, and z has a value in a range from greater than 0 to 0.05 and x+y+z&#x3c;1. The phosphor has a narrow emission centered at about 312 nm when excited by radiation from a low-pressure mercury discharge.

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Laceyville, PA, United States of America

Thomas M Snyder