Optical Properties of Defects

The influences of defects, which are generally created by the doping of materials, as well as their interactions with the dopant, are often neglected. In some materials, however, they show the most intense transitions, which are usually erroneously associated to those of present luminescent ions. Moreover, defects are often involved in very efficient energy transfer processes with the respective dopant. An understanding of the optical processes including defects has a huge importance for scintillators, which could be used as detectors in nuclear medicine or high-energy physics. We have recently begun to investigate the nature of the different defects and their optical properties in halide host lattices by means of UV/VIS and vibrational spectroscopy as well as EXAFS measurements.