Abstract

Luminescent Materials (Phosphors). Commercial phosphors are typically inorganic powders which convert some form of invisible exciting energy into visible light. For this reason and because they can be quite efficient energy converters, they are commonly used in lamps, television screens, display terminals, x-ray machines, and a variety of other applications. All of these types of phosphors are discussed in some detail. What phosphors consist of, how they work, how they are made, and some of the technological aspects of their production and use in each application are described. There are a wide variety of materials which luminesce under some form of excitation including common minerals and many organic dyes. However probably less than a hundred of these materials are efficient enough and maintain their efficiency well enough in the environment of their application to have any technological significance. All of these materials are inorganic compounds although there are many more organic compounds which fluoresce. The article is intended to be comprehensive but does not include specialized knowledge about certain phosphor materials or information on new or experimental phosphors or phosphor applications which are not widespread, eg, infrared-to-visible converting phosphors which although very interesting are used only in certain laser applications.