Luminescence of high-temperature yttrium-based superconductors

Luminescence spectra of thin films and single crystals of YBa"2Cu"3O"7"-"x high-temperature superconductors (HTSC) 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...
Ausführliche Beschreibung

Luminescence spectra of thin films and single crystals of YBa"2Cu"3O"7"-"x high-temperature superconductors (HTSC) 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 spectra the main contribution is made by a blue band with an energy of ~ 2.9 eV, which is, apparently, the luminescence inherent in the crystal. The time characteristics of luminescence were measured. It was found that 80% of all the luminescence has a very long (τ > 10^-^6 s) shaping time.A model of luminescence appearance is proposed, which is based on luminescence of oxygen quasimolecules formed during the decay of electronic excitations (luminescence of self-localized and defect-localized excitons). Ausführliche Beschreibung