A PROCESS FOR THE PREPARATION IMPROVED LONG DECAY IUMINESCENT POWDER USING A NOVEL COMPOSITION

摘要

A process for the preparation of improved long decay luminescent powder using a novel composition. The process related to the present invention involves the selection of a host material from group IIB-VIA compounds of periodic table either singly or a mixture of two or more, for example, oxides, sulphides, selenides, tellurides of zinc, cadmium and mercury, each of 99.99% purity, of size less than 100µm depending upon the application and the process of device application. The activators are selected from group IB or VIIB elements of the periodic table which can be copper, silver, gold and manganese, of 99.9% purity in the range of 1 -1000 ppm based on the required emission colour of the long decay luminescent powder.