Patent ID: 8815120
Filing Date: 2014-08-26
Classification: C09K,Y10T

Abstract:
1. A luminophore having an improved long-term stability, which absorbs radiation in a first wavelength range, and emits radiation in a second wavelength range that is different from the first wavelength range, wherein the luminophore is designed in the form of grains, and comprises an alkaline earth metal silicate of the general chemical formula EA x Si y O z as a base lattice, which is doped with an activator, wherein EA is formed by one or more alkaline earth metals, and the condition x, y, z>0 applies, wherein said base lattice is described by one of the following chemical formulas: (Ba EA′ EA and wherein the grains are chemically modified on their surface such that at least portions of their surface are formed by a chemical compound of the general formula EA u Z 2 , wherein the general formula can be represented by a formula in which the coefficients are mathematically abbreviated if the variable u is even; and wherein Z is formed by anions which can be chemically combined with cations of EA, and which are described by one or more of the following chemical formulas: SO 4 2− , PO 4 3− , CO 3 2− , C 2 O 4 2− , SiO 3 2− , and SiF 6 2− ; wherein u is equal to an ion charge of the anions Z.