ABSTRACT
The solid luminescent materials that convert energy into electromagnetic radiation, usually in the visible region, are termed as phosphor materials. The emission of electromagnetic radiation or light is called luminescence, which is the basic mechanism behind phosphors or luminescent materials. Based on various excitation sources, the luminescence has many classifications like photoluminescence, chemiluminescence, bioluminescence, radioluminescence, and electroluminescence. Phosphors are generally made from host lattices, in which a small amount of impurities or dopants or activators are added intentionally. These impurities can be transition metal ions, rare earth (RE) ions, or complex ions. Also, there is a vast area of host materials are available as silicates, oxides, titanates, molybdates, tungstates, and others. An efficient phosphor material for luminescence applications, we should choose suitable host material and activator ion. For this, there are a number of phosphor synthesis methods available, which affect the physical 302and luminescence properties of the phosphor material. Also, the phosphor materials find many applications in various fields and some of them include lighting applications, cathode ray tubes, scintillators, display devices, long persistent phosphors, light emitting diodes, organic fluorescent pigments, and others. This is the theme of this chapter.
In this chapter, we discuss about the phosphors, various luminescence and their basic mechanisms in Sections 14.1 and 14.2. Sections 14.3, 14.4, and 14.5 briefly introduce the importance and properties of activators (dopants), codopants, and host materials used in the phosphor material, respectively. Various phosphor synthesis methods and their advantages are explained in Section 14.6. Finally, Section 14.7 deals with various applications of phosphor materials and important optical properties of some of RE-doped oxide phosphors are also included.
