Photostimulated transformation of defects in cadmium iodide with copper and coactivators

The mechanism and nature of photochemical transformation in cadmium iodide with copper impurity crystal followed by optical properties changes were investigated. It was determined that the main mechanism of such transformations is photostimulated decay of ‘copper-defect’ complexes with low activation energy and forming of Cui defects which are the lightsensitivity and absorption centres. The influence of copper-including complexes formed by isomorphic and anisomorphic replacement in anionic and cationic sublattices on cadmium iodide crystal lightsensitivity was studied. It was determined that cationic Eu coactivator causes the light-insensitive defects forming, that is conditioned by [CuCd] centres stabilisation due to crystal lattice deformation by europium. The influence of anionic sulphur coactivator leads to absorption increase which is caused by single [Cui]-including defects and complexes stabilisation.