Luminescence properties of Ce-doped Cs2LiLaCl6 crystals

Time-resolved emission spectra, luminescence excitation spectra, and decay curves of Ce-doped and pure Cs-2 LiLaCl6 elpasolite-structure crystals measured under VUV excitation at 7 and 300 K are presented. The Cs2LiLaCl6 : Ce3+ crystal exhibits two basic emission bands: a 4.4-eV band with a decay constant of 1.4 ns related to core-valence (CV) transitions, and a 3.3-eV band with a decay constant of similar to 36 ns, which belongs to interconfiguration (5d --> 4f) transitions of Ce3+ ions. The widths of the valence and forbidden bands of Cs-2 LiLaCl6, are roughly estimated to be 3 and 8 eV, correspondingly. The presence of Li ions, efficient radiative CV transitions and the difference between the decay constants of the two emissions allow us to consider Cs-2 LiLaCl6: Ce3+ as a promising material for thermal-neutron detection with efficient neutron-gamma discrimination. (C) 2000 Elsevier Science B.V. All rights reserved.