Abstract
Luminescense spectra of thin films and single crystals of YBa 2Cu 3O 7−x high-temperature superconductors were measured under optical excitation by synchrotron radiation ( E = 10.2 eV) and by electrons (cathodoluminescence) with an energy of 6 keV. It has been shown that in all the spectra the main contribution is made by a blue band with an energy of ≈2.9 eV, which is, apparently, the luminescence inherent to the crystal. The time characteristics of luminescence were measured. It turned out that 80% of all the luminescence requires a very long time ( τ > 10 −6 s) to reach its final level. A model of luminescence appearance is proposed, which is based on luminescence of oxygen quasi-molecules formed by the decay of electronic excitations (luminescence of self-localized and defect-localized excitons).
Published Version
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