Luminescence and Luminescence Kinetics of Gd3Ga5O12 Polycrystals Doped with Cr3+ and Pr3+ |
| S. Mahlik, B. Kukliński, M. Grinberg
Institute of Experimental Physics, University of Gdańsk, Wita Stwosza 57, 80-952 Gdańsk, Poland |
| , L. Kostyk and O. Tsvetkova
Faculty of Electronics, Ivan Franko Lviv National University, Tarnovskovo 107, 79017 Lviv, Ukraine |
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| In this paper spectroscopic investigations of Gd3Ga5O12 (GGG) polycrystals, containing Cr3+ and intentionally doped with Pr3+ of concentrations 0.5, 1 and 1.5 mol% are presented. We have measured the steady state luminescence and luminescence excitation spectra, as well as the time resolved spectra and luminescence kinetics. The main goal was to investigate the excitation energy transfer from lattice to impurity and between impurities. We found that relative intensity of Cr3+ and GGG lattice luminescence decreased when material was doped with Pr3+. On the other hand, time resolved spectroscopy and luminescence decay measurements showed that the Cr3+ and GGG lattice luminescence decays were independent of Pr3+ content. The lifetime of Pr3+ luminescence related to 1D2 → 3H4 and 3P0 → 3H4 transitions decreased with concentration of Pr3+, which was attributed to the concentration luminescence quenching. No energy transfer between GGG lattice defects and Cr3+, and Pr3+ ions was observed. We proposed the model of radiative recombination of electron and hole, which took place through three independent pathways: by GGG host emission that peaked at 12750 cm-1, by Cr3+ luminescence that peaked at 15400 cm-1, and by Pr3+ luminescence. |
| DOI: 10.12693/APhysPolA.117.117 PACS numbers: 78.55.Hx, 78.60.Kn, 78.70.En |