Werner Urland

Abstract:

Phosphors doped by divalent or trivalent lanthanides are in the spotlight of scientific investigations due to its possible applications as domestic lighting, laser materials, or scintillator crystals. Quantum chemical calculations (semi-empirical and non-empirical) are used to design new phosphors by predicting their luminescence properties. The model using Density Functional Theory is based on an effective Hamiltonian that includes electrostatic, spin-orbit, and ligand field contributions. From these calculations the multiplet energy levels arising from the ground [Xe]4fⁿ and excited [Xe]4f^n-15d¹ electron configurations of Ln²⁺ and Ln³⁺ in their chemical environment are obtained. The results are in good agreement with the experimental investigations, validating the usefulness of the theoretical modelling to understand and characterize the luminescence spectra of phosphors.