Origin of the green persistent luminescence of Eu-doped SrAl2O4 from a multiconfigurational ab initio study of 4f7 → 4f65d1 transitions. Issue 25 (29th May 2018)

• Record Type: Journal Article
• Authors: Ning, Lixin; Huang, Xiaoxiao; Huang, Yucheng; Tanner, Peter A.
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 25(2018)
• Page Start: 6637
• Page End: 6640
• Publication Date: 2018-05-29
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8tc02141d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The green persistent luminescence from SrAl2 O4 :Eu is assigned to Eu 2+ at the Sr2 site based on a multiconfigurational ab initio study. Abstract : The green persistent luminescence of Eu 2+ in SrAl2 O4 has been widely applied in self-sustained night vision due to its long duration and ability to be excited by sunlight. However, the question of which substitutional site in the lattice is responsible for the green emission remains unresolved. Herein, we perform multiconfigurational ab initio calculations at the CASSCF/CASPT2 level with the spin–orbit effect on 4f 7 → 4f 6 5d 1 (4f → 5d) transitions of Eu 2+ located at the Sr1 and Sr2 sites of SrAl2 O4 . By comparison of the calculated transition energies with data from experimental low-temperature excitation spectra, the green luminescence is unambiguously assigned to Eu 2+ at the Sr2 site. In addition, by using the present results as a calibration, the accuracies of the literature-reported DFT-based approaches to the Eu 2+ 4f → 5d transition energies are discussed. This investigation is expected to motivate more exploration of multiconfigurational ab initio methodology to elucidate luminescence properties of Eu 2+ -activated complex phosphors.