Method of manufacturing a rare-earth doped alkaline-earth silicon nitride phosphor, rare-earth doped alkaline-earth silicon nitride phosphor obtainable by such a method and radiation-emitting device comprising such a rare-earth doped alkaline-earth silicon nitride phosphor

摘要

The invention relates to a method of manufacturing a rare-earth (RE) doped alkaline-earth silicon nitride phosphor (AE₂Si₅N₈) 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:IRE) bringing the compounds at an elevated temperature in reaction for forming the rare-earth doped alkaline-earth silicon nitride phosphor (AE₂Si₅N₈:RE), a small amount of oxygen, whether intentionally or not-intentionally added, being incorporated in the rare-earth doped alkaline-earth silicon nitride phosphor (AE₂Si₅N₈:RE) thus formed.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) suitable further elements of the periodic system by which vacancies are created, filled or annihilated resulting in the formation of a modified alkaline-earth silicon nitride phosphor (AE₂Si₅N₈) having a stoichiometric composition. In this way a modified phosphor is obtained having excellent and stable optical properties. The invention further comprises a modified phosphor obtainable by a method according to the invention and a radiation-emitting device comprising such a phosphor.