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Journal of Physical Studies 9(1), 96–99 (2005)
DOI: https://doi.org/10.30970/jps.09.96 LUMINESCENCE OF THE PURE AND CERIUM-DOPED Cs3LaI6 SINGLE CRYSTALSM. Pydzyrailo, V. Vistovsky, G. Stryhanyuk
Ivan Franko National University of Lviv, |
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The studies of luminescence and the luminescence excitation spectra of the pure and Ce$^{3+}$-doped Cs$_3$LaI$_6$ single crystals at 9 and 77 K are reported. The doublet band of STE emission (maxima at 2.57 and 2.81 eV) was revealed in the luminescence spectrum of pure Cs$_3$LaI$_6$ crystal at 9 K. The band gap value (4.3 eV) has been estimated for the Cs$_3$LaI$_6$ crystal taking into account the presence of characteristic dip in the excitation spectrum of STE emission at 3.85 eV caused by the excitonic reflection. The doping of the Cs$_3$LaI$_6$ crystal by Ce$^{3+}$-ions results in the appearance of the cerium doublet (peaking at 2.57 and 2.81 eV) as well as the near-impurity localized exciton band (3.60 eV) in the luminescence spectra at 9 K. The slow decay component ($τ$ > 150 ns) dominates in the cerium emission under the excitation in the fundamental absorption range that confirms the excitation energy transfer from the crystalline matrix to the impurity centres.
PACS number(s): 78.55.Hx, 78.40.Ha, 71.35.Cc