ALKALINE EARTH METAL SILICATE LUMINOPHORE AND METHOD FOR IMPROVING THE LONG-TERM STABILITY OF AN ALKALINE EARTH METAL SILICATE LUMINOPHORE

The present invention relates to a method for improving the long-term stability of an alkaline earth metal silicate luminophore. The luminophore is formed in the form of grains and has a basic grid of the general chemical formula EAxSiyOz with x, y, z > 0. The component EA is formed by one or more alkaline earth metals. An activator is doped into the basic grid. In a step of the method, the grains of the luminophore are heated in a reactor chamber (01). A volatile organoaluminum compound is heated and flowed through with a first carrier gas, as a result of which a first carrier gas mixture containing the volatile organoaluminum compound is obtained. In addition, water is heated and a second carrier gas flows through, as a result of which a second carrier gas mixture containing the water is obtained. The first carrier gas mixture and the second carrier gas mixture are introduced into the reactor chamber (01) where the grains of the alkaline earth metal silicate luminophore are enveloped by the carrier gas mixtures. As a result, the volatile organoaluminum compound and the water react with one another at least predominantly to form aluminum oxide hydroxide which forms a coating of the grains of the alkaline earth metal silicate luminophor. The invention further relates to an alkaline earth metal silicate luminophore.