Rca Inc.

Sarnoff Corporation

Perry Neil Yocom

James G Kane

Diane Zaremba

William E Harty

Red and orange-red emitting long persistence phosphors based on strontium sulfide and activated with a divalent rare earth such as europium, can be made by heating in the presence of an ammonium halide, or a trivalent rare earth. Using ammonium halide as the flux, the red-emitting phosphor can be molded into a desired shape. Using ammonium halide and powdered alumina, the red-emitting phosphor can be made into a powder directly. Heating a rare earth activated (Eu) strontium sulfide in the presence of a trivalent rare earth salt in the presence of sulfur and a source of carbon, fine particle size red-emitting phosphor particles can be made.

Long persistence red phosphors

An electroluminescent film of an activated alkaline earth metal sulfide phosphor is produced by a method utilizing low temperatures for substrate protection and achieving excellent crystallinity and enhanced brightness. A layer of an alkaline earth metal halide and a suitable activatior is deposited on the substrate, heated to melt the halide and treated with gaseous hydrogen sulfide to form the phosphor. A precursor for the halide may be deposited on the substrate heated to melting temperature and treated with gaseous hydrogen halide to form the halide in-situ.

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Princeton, NJ, United States of America

Perry Neil Yocom