Effect of Point Defects on Luminescence Characteristics of ZnO Ceramics

P. A. Rodnyi, K. A. Chernenko, A. Zolotarjovs, L. Grigorjeva,
E. I. Gorokhova, and I. D. Venevtsev

Abstract—Photo- and thermally stimulated luminescence of ZnO ceramics are produced by uniaxial hot pressing. The luminescence spectra of ceramics contain a wide band with a maximum at 500 nm, for which oxygen vacancies VO are responsible, and a narrow band with a maximum at 385 nm, which is of exciton nature. It follows from luminescence excitation spectra that the exciton energy is transferred to luminescence centers in ZnO. An analysis of the thermally stimulated luminescence curves allowed detection of a set of discrete levels of point defects with activation energies of 25, 45, 510, 590 meV, and defects with continuous energy distributions in the range of 50–100 meV. The parameters of some of the detected defects are characteristic of a lithium impurity and hydrogen centers. The photoluminescence kinetics are studied in a wide temperature range.
DOI: 10.1134/S1063783416100309

ISSN 1063-7834,

Physics of the Solid State, 2016, Vol. 58, No. 10, pp. 2055–2061.

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Defect Luminescence of YAG Nanopowders and Crystals

L. Grigorjeva, D. Jankoviča, K. Smits, D. Millers, S. Zazubovich

Undoped and rare-earth-ion-doped Y3Al5O12 (YAG) nanopowders are prepared by the sol-gel low-temperature combustion method. The luminescence characteristics of the YAG, YAG:Ce, YAG:Pr, and YAG:Ce/Pr nanopowders are compared with those of the single crystals. The luminescence band peaking around 3.1 eV is complex and excited at about 3.6 eV, 3.9 eV and 4.3 eV. The 3.1 eV emission was peculiar to all the samples studied. The Stokes shift of this band is ~0.5 eV. The decay time of the ~3.1 eV emission at 80 K is ~14 ns and the slower decay (afterglow) components are practically absent. The 3.1 eV luminescence was suggested to arise from different intrinsic lattice defects.

Latvian Journal of Physics and Technical Sciences 2012, N 4

DOI: 10.2478/v10047-012-0022-4

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Luminescence of oxygen related defects in zirconia nanocrystals

K. Smits, L. Grigorjeva, W. Łojkowski, and J. D. Fidelus

The luminescence of undoped tetragonal structure ZrO2 nanocrystals was studied. The luminescence intensity
depends on oxygen content in gases mixture in which the nanocrystals were annealed. The distorted
Zr-O bond is suggested to be the recombination center for band carriers. The oxygen deficient defect
is proposed to be responsible for photoluminescence.

Physica Status Solidi (C) Current Topics in Solid State Physics 4, No. 3, 770– 773 (2007)

DOI 10.1002/pssc.200673850

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