LUMINESCENT POWDER, METHOD FOR PRODUCING THE LUMINESCENT POWDER AND LUMINESCENT BODY PROVIDED WITH LUMINESCENT POWDER

摘要

The luminescent powder (1) comprises luminescent particles (2) having an average luminescent particle size (3) selected from a range starting from 0.1 ñm, inclusive, to 5.0 ñm, inclusive, and is characterized in that the luminescent particles comprise primary particles (4) having an average primary particle size (5) selected from a range starting from 0.1 ñm, inclusive, to 1.0 ñm, inclusive. The primary particles, which consist of, for example, an yttrium-aluminum garnet (Y3Al5O12) doped with cerium, are agglomerated to form the luminescent particles. The method for producing the luminescent power comprises the following steps: a) providing at least one precursor of the primary particles; b) preparing the primary particles from the precursor of the primary particles, and; c) forming the luminescent particles of the luminescent powder from the primary particles. The precursor for Y3Al5O12 is, for example, a powder mixture consisting of hydroxides. In order to prepare the precursor, the hydroxides are precipitated out of a sulfuric acid metal-containing solution by adding a basic ammonia solution drop-by-drop. The precipitate is dried and subsequently calcined thereby forming primary particles and simultaneously agglomerating them to form the luminescent particles of the luminescent powder.