Osram Sylvania Inc.

Gte Products Corporation

Vaddi B Reddy

Ronald E Karam

Shellie K Northrop

Kenneth T Reilly

Ha K Cheung

Gregory A Marking

James R Cox

Ru-Yi Qi

Cheryl M Forster

Yan Zhang

Nathaniel E Brese

Barry G DeBoer

Joseph A Cooper

An electroluminescent phosphor containing an alkali iodide dopant, such as lithium iodide or potassium iodide, and having CIE coordinates of x=0.173 to 0.187 and y=0.392 to &lt;0.424. The phosphor without alkali iodide dopant has CIE coordinates of x.apprxeq.0.180 to 0.184 and y.apprxeq.0.424 to 0.426. The method of making the phosphor includes adding the alkali iodides during a second firing step.

Alkali iodide doped zinc sulfide electroluminescent phoshor

A composition and method are provided for reducing the persistence of yttrium tantalate x-ray phosphors having the monoclinic M' structure. Persistence is reduced by incorporating a molybdenum or vanadium additive into the phosphor. The method for incorporating the molybdenum or vanadium additive consists of adding a molybdenum or vanadium containing compound to the mixture of raw materials formulated to make the phosphor and firing the mixture at a temperature and for a time sufficient to form the phosphor.

Yttrium tantalate x-ray phosphors with reduced persistence

A composition and method are provided for reducing the persistence of yttrium tantalate x-ray phosphors having the monoclinic M' structure. Persistence is reduced by incorporating a tungsten additive into the phosphor. The phosphor preferably contains at least about 4 ppm W. The method for incorporating the tungsten additive consists of adding a tungsten containing compound to the mixture of raw materials formulated to make the phosphor and firing the mixture at a temperature and for a time sufficient to form the phosphor.

The brightness of small size terbium activated gadolinium oxysulfide (Gd.sub.2-x Tb.sub.x O.sub.2 S) phosphor is increased by the incorporation of a lithium dopant. The lithium dopant is added to the phosphor by mixing lithium phosphate with the raw materials formulated to make the phosphor.

Lithium doped terbium activated gadolinium oxysulfide phosphor

A monoclinic M' yttrium tantalate x-ray phosphor containing a dopant selected from silicon or germanium to increase phosphor particle size and/or brightness. The phosphor is made by adding a silicon- or germanium-containing compound and a flux to the mixture of raw materials formulated to make the phosphor and then firing the doped mixture at a temperature and for a time sufficient to make the phosphor.

Yttrium tantalate x-ray phosphors with increased luminance and particle

Phosphor lag was reduced to acceptable levels in high lag monoclinic M' yttrium tantalate x-ray phosphors through the addition of minor amounts europium to the phosphors. In particular, europium was added to yttrium tantalate phosphors containing terbium and to phosphors formulated with a stoichiometric excess of yttrium.

Reduction of lag in yttrium tantalate x-ray phosphors

An improved blue-green emitting ZnS:Cu,Cl phosphor is made by doping the phosphor with small amounts of gold and increasing the amount of low intensity milling between firing steps. The improved phosphor has better halflife and brightness characteristics while maintaining its desired emission color.

Improved blue-green emitting ZnS:Cu,Cl electroluminescent phosphor and

A improved ZnS:Cu electroluminescent phosphor having a halflife of at least about 900 hours. The halflife improvement is made by doping the phosphor with minor amounts of gold and substantially increasing the amount of low intensity milling between firing steps. The improved phosphor has a dramatically longer halflife without sacrificing brightness or exhibiting large shifts in emission color.

ZnS:Cu electroluminescent phosphor and method of making same

Electroluminescent phosphors having substantially increased luminance and maintenance over that of prior art electroluminescent phosphors may be made by (1) doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces, with selected activator ions capable of luminescent emission, and (2) introducing organic monomers or other conductive material into the vacant spaces of the atomic structure of the doped inorganic intercalation compound. The organic monomers may be polymerized in situ to form conductive polymers therein.

Phosphor and method of making same

Inorganic intercalation phosphors were made by doping an inorganic intercalation compound having an atomic structure interspersed with vacant spaces with selected activator ions capable of luminescent emission when excited by ultraviolet light and/or cathode rays.

The brightness and particle size of a niobium-activated yttrium tantalate x-ray phosphor can be increased by the addition of either barium fluorosilicate or calcium fluorosilicate thereto.

Method of making niobium-activated yttrium tantalate x-ray phosphor

Method of preparing fluoroplogopite phosphor

An unactivated yttrium tantalate phosphor, M'YTaO.sub.4, contains one or more additives of Sr, Rb and Al in order to improve brightness under X-radiation.

Growing community of inventors

Sayre, PA, United States of America

Vaddi B Reddy