Abstract
LaI3:Ce3+ has the smallest band gap in the
LaX3:Ce3+ (X=F, Cl, Br, I) series and hence a
potentially higher scintillation yield. The luminescence properties of
LaI3:Ce were investigated by means of optical, X-ray, and
γ-ray excitation. Unexpectedly, the compound is a poor
scintillator at room temperature but presents good scintillation
properties for temperatures below 100 K where Ce3+ emission
is observed peaking at 452 and 502 nm with a yield of ˜16 000
photons/MeV. The drastic thermal quenching of luminescence is explained
by the proximity of the Ce3+ lowest 5d excited state to the
host conduction band. Autoionization of Ce3+ therefore
prevents any scintillation effect at room temperature. The positions of
Ce3+ levels relative to the host bands were estimated.
Original language | English |
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Pages (from-to) | 22-26 |
Journal | Nuclear Instruments and Methods in Physics Research Section A |
Volume | 537 |
DOIs | |
Publication status | Published - 1 Jan 2005 |
Keywords
- Iodide
- Ce3+
- γ-detection
- Rare-earth trihalides
- Scintillation crystals