| The Way to White Light Emitting Diodes by Quantum Chemical Calculations Werner Urland1; 1PRIVATE INSTITUTE OF THEORETICAL CHEMICAL PHYSICS, Muralto, Switzerland; PAPER: 26/Chemistry/Regular (Oral) SCHEDULED: 12:10/Sat. 26 Oct. 2019/Aphrodite A (100/Gr. F) ABSTRACT: Quantum chemical calculations (semi-empirical and non-empirical) are used to design new phosphors with Eu <sup>2+</sup> for white Light Emitting Diodes (LEDs) used for artificial lighting. This is of ultimate importance as the quest for optimal white LEDs is still relevant. The model which uses Density Functional Theory is based on an effective Hamiltonian that includes electrostatic, spin-orbit and ligand field contributions. From these calculations, the multiple energy levels arising from the ground 4f7 and excited 4f65d1 electron configurations of Eu<sup>2+</sup> in their chemical environment are obtained. The results are in good agreement with the experimental investigations, validating the usefulness of theoretical modelling to understand and characterize the luminescence spectra of phosphors with Eu<sup>2+</sup>. [1,2] The luminescence properties of the new phosphor BaSnSi<sub>3</sub>O<sub>9</sub>:Eu<sup>2+</sup> have been theoretically predicted and then experimentally verified. [3] References: 1. A. Garcia-Fuente, F. Cimpoesu, H. Ramanantoanina, B. Herden, C. Daul, M. Suta,<br /> C. Wickleder, W. Urland, Chem. Phys. Lett. 622, 120 (2015)<br />2. H. Ramanantoanina, F. Cimpoesu, C. Göttel, M. Sahnoun, B. Herden, M. Suta,<br /> C. Wickleder, W. Urland, C. Daul, Inorg. Chem. 54, 8319 (2015).<br />3. A. Garcia-Fuente, F. Baur, F. Cimpoesu, A. Vega, T. Jüstel, W. Urland,<br /> Chem. Eur. J. 24, 16276 (2018). |
