Exciton‐related luminescence in LuAG:Ce single crystals and single crystalline films

Abstract

Luminescence of the excitons and the role of anti‐site defects, as well as the peculiarities of energy transfer to the Ce3+ activator ions were investigated in Lu3Al5O12:Ce compound. The measurements of time–resolved emission spectra and decay kinetics at 9 K and 300 K under the excitation by synchrotron radiation were used. The characteristics of single crystals and single crystalline films of Lu3Al5O12:Ce were compared and differences explained in the light of substantially different concentrations of the anti‐site defects in the same material prepared by different technologies. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Single crystalline film scintillators based on Ce- and Pr-doped aluminium garnets

“…This indicates that the Ce 3+ emission in YAG:Ce and LuAG:Ce SCF can be excited mainly through the creation of bound exciton states contrary to SC, where the energy transfer via AD excitation is very significant. Existence of two excitation maxima of the Ce 3+ emission in LuAG:Ce SCF provides an indication that the RES of an exciton bound around Ce 3+ ions has two radiative levels (Zorenko et al, 2005b). Thus, from the data shown in Figs.…”

Luminescence and Tb3+–Ce3+–Eu3+ ion energy transfer in single-crystalline films of Tb3Al5O12:Ce,Eu garnet

“…6a, curve 1) with a lifetime of 57 ns. It should be noted that such a lifetime of the Ce 3+ emission in TbAG host (57 ns) is small in comparison with the analogous magnitudes 66.5 and 49 ns for YAG [12] and LuAG [13] SCFs with maxima of the Ce 3+ luminescence at l max ¼ 530 and 515 nm, respectively. Taking into account the fact that the decay time of the radiative 5d 1 -4f of Ce 3+ transition depends on the wavelength of radiation as t$f(l) [14], one should expect the value of t for the Ce 3+ luminescence in TbAG (l max ¼ 563 nm) to be around tX100 ns.…”

On the synthesis of LuAG:Ce fine powders by molten salts methods and spectroscopic properties of the products

“…Their relative contributions were also similar with the shorter component comprising about 25% of the emitted light. Note, that the longer component has value similar to single crystals ($ 60-70 ns) [7,14]. These numbers may imply that about 50% of Ce 3 þ ions incorporated into the LuAG host suffer from a kind of luminescence quenching.…”

“…Since these defects appear mostly as a result of high-temperature treatment, development of fabrication techniques of good quality LuAG:Ce at reduced temperatures is important. The anti-site defects are blamed for afterglow in LuAG:Ce as well as reduced emission efficiency due to generation of nonradiative pathways of energy dissipation [6,7].…”