Abstracts 2004

Abstract of Publication No. 472

A. Bessière, P. Dorenbos, C. W. E. van Eijk, L. Pidol, K. W. Krämer and Hans U. Güdel
Spectroscopy and anomalous emission of Ce doped elpasolite Cs2LiYCl6
J. Phys.: Condens. Matter, 16, 1887-1897 (2004)      Full Text (PDF)      DOI-Link     

Abstract: A 10 ns fast luminescence was observed at 270 nm in Cs2LiYCl6:Ce3+ in addition to the 5dt–4f Ce3+ doublet emission at 370 and 405 nm. This anomalous luminescence occurs exclusively for an excitation of the 4f–5de transitions of Ce3+ around 210 nm. It is not excited under across band gap excitation which makes it an uncommon phenomenon. The emission shows a large Stokes shift of 1.2 eV that must be related to an excited state with a very strong electron–lattice interaction or possible involvement of conduction band states. The 270 nm emission undergoes thermal quenching between 140 and 250 K while the 5dt–4f Ce3+ emission gains intensity. The shape of the decay time spectra of the 5dt–4f Ce3+ emission reflects a temperature activated transfer from the anomalous state to the 5dt lowest Ce3+ level.

Last modified: 13.12.11 by Gabriela Frei