Rare-earth doped alkaline-earth silicon nitride phosphor, method for producing and radiation converting device comprising such a phosphor

US8551360B2 · kind B2 · utility

Assignees

• LEUCHTSTOFFWERK BREITUNGEN GMBH · DE
• Ledon Lighting Jennersdorf GmbH · AT

Inventors

• Cheng-Jun Duan · Barchfeld-Immelborn, DE
• Hubertus Theresia Hitzen · Eindhoven, NL
• Sylke Rösler · Eisenach, DE
• Detlef Starick · Berlin, DE
• Sven Rösler · Eisenach, DE
• Anne Charlotte Antoinette Delsing · Eindhoven, NL

Key dates

• Filing date: Oct 14, 2008
• Grant date: Oct 8, 2013
• Expiry date: May 1, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09K11/77348
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a method of manufacturing a rare-earth doped alkaline-earth silicon nitride phosphor of a stoichiometric composition. Said method comprising the step of selecting one or more compounds each comprising at least one element of the group comprising the rare-earth elements (RE), the alkaline-earth elements (AE), silicon (Si) and nitrogen (N) and together comprising the necessary elements to form the rare-earth doped alkaline-earth silicon nitride phosphor (AE2Si5N8:RE). The method further comprises the step of bringing the compounds at an elevated temperature in reaction for forming the rare-earth doped alkaline-earth silicon nitride phosphor (AE2Si5N8:RE). In such a method normally a small amount of oxygen, whether intentionally or not-intentionally added, will be incorporated in the rare-earth doped alkaline-earth silicon nitride phosphor (AE2Si5N8:RE). According to the invention the creation of defects by formation of a non-stoichiometric oxygen containing phosphor is at least partly prevented by partly substituting for the ions (AE, Si, N) of the alkaline-earth silicon nitride phosphor (AE2Si5N8:RE) suitable further elements of the periodic system by which …