Patent Number: 6,254,806

Title: High efficiency polycrystalline phosphors and method of making same

Abstract: A phosphor is provided that has a host material that is doped with a dopant having the chemical structure XCl.sub.3, where X is a rare earth element or combination of elements. A free oxygen contributor is also added to provide the free oxygen necessary to activate the rare earth dopant. The processing of the phosphor includes the heating of the phosphor in an over pressure environment of zinc, cadmium or tellurium. The heating is done in a two-temperature zone enclosed environment, so that impurities in the phosphor powder are condensed out on the cooler surface. Altematively, the dopant may be a material that does not include a rare earth element, such as copper, tellurium, cadmium, silver, potassium, manganese, magnesium, calcium, strontium, and barium.

Inventors: Valdna; Vello (Tallinn, EE), Durst; Roger D. (Middleton, WI)

Assignee: Bruker AX, Inc.

International Classification: C09K 11/88 (20060101); C09K 11/77 (20060101); C09K 011/54 (); C09K 011/88 ()

Expiration Date: 07/03/2018