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arXiv · 1101.0524

Time-resolved spectroscopy of exciton states in single crystals, single crystalline films and powders of YAlO_3 and YAlO_3:Ce

V. Babin·L. Grigorjeva·I. Kondakova·T. Kärner·V. V. Laguta·M. Nikl·K. Smits·S. Zazubovich·Yu. Zorenko
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Abstract

Luminescence characteristics of single crystals (SC), single crystalline films (SCF), powders and ceramics of YAlO_3 and YAlO_3:Ce have been studied at 4.2-300 K under photoexcitation in the 4-20 eV energy range and X-ray excitation. The origin and structure of defects responsible for various exciton-related emission and excitation bands have been identified. The ~5.6 eV emission of YAlO_3 SCF is ascribed to the self-trapped excitons. In YAlO_3 SC, the dominating 5.63 eV and 4.12 eV emissions are ascribed to the excitons localized at the isolated antisite defect Y^{3+}_Al and at the Y^{3+}_{Al} defect associated with the nearest-neighbouring oxygen vacancy, respectively. Thermally stimulated release of electrons, trapped at these defects, takes place at 200 K and 280 K, respectively. The formation energies of various Y^{3+}_{Al}-related defects are calculated. The presence of Y_{Al} antisite-related defects is confirmed by NMR measurements. The influence of various intrinsic and impurity defects on the luminescence characteristics of Ce^{3+} centers is clarified.

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V. Babin, L. Grigorjeva, I. Kondakova, T. Kärner, V. V. Laguta, M. Nikl, K. Smits, S. Zazubovich, Yu. Zorenko. 2011-01-03. Time-resolved spectroscopy of exciton states in single crystals, single crystalline films and powders of YAlO_3 and YAlO_3:Ce. https://doi.org/10.1088/0022-3727%2F44%2F31%2F315402

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