Taken into account the presences of Li vacancy (VLi), calculations were made of the formation energy, electronic structure and optical properties of Cu-doped LiF (LiF:Cu) by using the density functional theory. The presence of VLi led to a decrease of the formation energies of Cu, in favor of Cu doping into LiF. Due to Cu doping, an impurity band of Cu-3d states was formed at the Fermi level, which was then split by the introduction of VLi. A wide absorption band and some new absorption peaks were obtained in LiF:Cu with an adjacent VLi to Cu. There appears an absorption peak at 9.3 eV, which was consistent with the experiment observation (133 nm). The results were useful for understanding of the optical properties of the doped systems.

First-Principles Study on Electronic and Optical Properties of Cu-doped LiF with Li Vacancy. Y.K.Sun, J.H.Zhang, J.W.Ding, X.H.Yan: Physica B, 2012, 407[13], 2458–61