Cu+ Luminescent Centre in LiCl Single Crystals

Abstract Using the cluster approximation, a detailed semi‐empirical molecular orbital calculation is reported for computing the energy levels of Cu + luminescent centres in NaCl and LiCl. Excited states energies are obtained on the basis of 3d 9 4s configuration of Cu + , including spin–orbit interaction. Excitation and emission bands of LiCl:Cu + are reported and their assignments are discussed. The emission process is studied by measuring lifetimes of the emitting level at various temperatures. The energy level scheme provides a satisfactory explanation of the emission process, with the presence of active metastable levels, in agreement with the decay time data.