Luminescence and Energy Transfer in Lu3Al5O12 Scintillators Co-Doped with Ce3+ and Tb3+

• DOI: 10.1021/jp301337f
• Publication Date: 2012-07-26T15:08:19Z
• Authors: Joanna M. Ogiegło; Aleksander Zych; Konstantin V. Iva...; Thomas Jüstel; Cees R. Ronda; Andries Meijerink
• Keywords: Terbium; Praseodymium

Lu(3)Al(5)O(12) (LuAG) doped with Ce(3+) is a promising scintillator material high density and fast response time. The light output under X-ray or γ-ray excitation is, however, well below the theoretical limit. In this paper influence of codoping Tb(3+) investigated aim to increase output. High resolution spectra singly LuAG (with Tb(3+)) are reported provide insight into energy level structure two ions in LuAG. For zero-phonon lines vibronic observed for lowest 5d bands Stokes' shift (2 350 cm(-1)) Huang-Rhys coupling parameter (S = 9) have been determined. 4f-5d transitions spin (HS) low (LS) states (including line vibrational state). HS-LS splitting 5400 cm(-1) smaller than usually explained by reduction 5d-4f exchange J covalency. Upon replacing Lu(3+) ion larger ion, crystal field increases, causing state (5)D(4) allowing efficient transfer from down temperatures. Luminescence decay measurements confirm qualitative understanding process. Co-doping does not result desired output, an explanation based on electron trapping defects discussed.