Electronic excitations and luminescence of Y1Ba2Cu307 superconducting metal-insulator ceramics
Lushchik Ch.B, Kuusmann I. L , Fel'dbakh E. Kh., Vallaste K. E. , Liblik P. Kh. , Maaroos A. A., Meriloo I. A. , Savikhina T. I.
Luminescence and nonradiative transitions accompanied by the production of defects have been observed for the first time in a superconducting metal-insulator system in which a broad energy gap lies above a nearly filled valence band. The particular material was Y1Ba2Cu307. At 10 K, an emission is observed at 3.355 eV. This emission may involve a Bose condensation of biholes.