Dielectric Phenomena in Solids

3.4 Luminescence

Luminescence was known and studied long before the discovery of the quantum picture of atoms by Rutherford and Bohr. Luminescent spectra can provide information about the nature, structure, and excited states of an atom or a molecule in a solid. Luminescence and its related phenomena have been technically employed for various optical devices, including scintillation counters, electroluminescent devices, etc. The process of luminescence is the de-excitation of excited atoms or molecules (or the annihilation of excitons through recombination) by reemission of the absorbed energy as light. Whatever the form of the energy input to the luminescent materials, the final stage in the process is an electronic transition between two ...