ABSTRACT
This chapter deals with the different types of luminescence found in the novel systems and in particular the electroluminescence of high-Tc oxide superconductors. The luminescence of oxygen-dominated lattices has been observed for many years in naturally occurring phosphates, silicates, carbonates and other materials. Oxygen-dominated lattices are those in which oxygen is a major chemical constituent of host lattice. The oxygen-dominated lattices showing luminescence are generally wide-band gap semiconductors or insulators. Luminescence is mainly associated with the optical transitions of the ions either of the host or impurity in a system. The cathodoluminescence in scanning electron microscope is a well-established tool concerning semiconducting materials.
