Investigation of the microstructure and electronic features for Ce3+-doped YAG crystal: A first-principle study

The Ce3+-doped YAG crystal has drawn considerable interest because of its important application in the white light-emitting diodes. However, the fundamental understanding of its microstructure is still lacking. In this work, the structural evolution and electronic properties of Ce3+-doped YAG crystal are systematically studied on the basis of the density functional theory (DFT) as well as Crystal structure Analysis by Particle Swarm Optimization (CALYPSO) method. A novel stable phase with cage-like structure and C-222 space group of Ce3+-doped YAG crystal has been reported. The calculations of the electronic band structure indicate that the Ce3+-doped YAG possesses a conductive character because the Fermi level is crossed through by the conduction band. By analyzing the electronic density of states (DOS), we conclude that the reason of the elimination of the insulated character can be attributed to the impurity Ce3+. The bond character between the Ce-O and Y-O are identified by the calculation of the electron localization function (ELF). These results can offer significant information for exploring new rare-earth doped laser materials and also provide useful insights to elucidate some experimental phenomena.