Abstract
Confocal microscopy was exploited to study spatial distribution of luminescence characteristics in Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> :Ce (LSO:Ce) and mixed Lu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2x</sub> Gd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-2x</sub> SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> :Ce (LGSO:Ce) crystals. Spatial distributions of spectrally-integrated photoluminescence (PL) intensity, PL band peak and spectral center of mass positions, and band width were determined. In both crystals, the luminescence spectra at 405 nm excitation are dominated by one broad band peaked at ~ 510 nm, while a long-wavelength shoulder is also observed in LGSO:Ce. Spatial inhomogeneities of the order of 1-3 micron in diameter are observed for the band position in LGSO:Ce. A comparative analysis of the spectra shows that the inhomogeneity is caused by spatial distribution in the spectral component at 500-700 nm, which may be attributed to Ce <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> located in CeO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> polyhedra (Ce2), or, more probably, to some defects in the crystal. Our results indicate that the changes in luminescence spectrum shape reflect Lu/Gd ratio fluctuations on a micrometer scale in the bulk of the mixed LGSO:Ce crystals.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call