Ab initio calculations on the local structure and the 4f–5d absorption and emission spectra of Ce 3 + -doped YAG

• Published in: Journal of luminescence Vol. 128; no. 8; pp. 1248 - 1254
• Main Authors: Gracia, Jose, Seijo, Luis, Barandiarán, Zoila, Curulla, Daniel, Niemansverdriet, Hans, van Gennip, Wouter
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2008
• Subjects: 4f–5d Spectra; Ab initio; Absorption; Emission; formula omitted; Local structure; Spin–orbit; YAG; Ce ( 3 + ); Local structure; Ab initio; Absorption; Spin–orbit; 4f–5d Spectra; Emission; YAG
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/j.jlumin.2007.12.027

The 4 f ↔ 5 d absorption and emission spectra of Ce 3 + -doped YAG ( Y 3 Al 5 O 12 ) are simulated with a quantum chemical ab initio embedded cluster approach applied to Ce 3 + substitutional defects of D 2 local symmetry. The only empirical information used is the structure of the pure host. The simulated absorption spectrum is calculated with overestimations of 2300– 3300 cm - 1 , which became 4600 cm - 1 in the luminescence. The three 4 f → 5 d observed absorptions were assigned and the energies of the two remaining ones, which are hidden by the absorption of the pure host, were predicted. The lowest 5 d → 4 f emission was found to take place from Γ 5 ( 2 2 A ) and the next emission from Γ 5 ( 3 2 B 3 ). Good absorption and emission band shapes and relative intensities are obtained. A large underestimation of the Stokes shift is found, which suggests an underestimation of the relaxation on the emitting state.