Defect and spectroscopy properties of Eu-doped RbBaPO4 phosphors: A computer simulation study

The effects of Eu incorporation in the RbBaPO4 structure was investigated using atomistic simulation based on lattice energy minimization combined with crystal field models. The defect study reveals that the most favorable intrinsic defect type is formed by the anti-site defect. The results revealed that Eu3+ prefers to enter the Ba site with a RbBa' anti-sites as charge compensation. Crystal field theory shows that the substitution of the Eu3+ ion for the Ba2+ ion in the anti-site defect accompanied by the local lattice deformation induces a local symmetry without the inversion center of the slightly distorted C4 type at the position of the impurity Eu3+ ion. The 7F1 and 7F2 energy sublevels as well as the 7F1 manifold were satisfactorily reproduced with a set of phenomenological charge factors and non-null crystal field parameters.