Fluorescence from anion vacancies in SrO

Abstract Illumination into the F + optical absorption band at 3.1 eV in either proton or neutron irradiated SrO produces a photoluminescence band centered at 2.5 eV, with a half-width of 0.34 eV at 5 K. The radiative lifetime of the 2.5 eV fluorescence is found to be 0.42 μ sec. Calculations have been made of the electronic structure of the F + center using a model which emphasizes the importance of (a) electronic structure on the ions neighboring the defect, (b) electronic and ionic polarization of the lattice, and (c) lattice distortion and its effects on the energy levels and wave functions of the defect. The calculation predicts that in absorption the 2 T 1 u state, to which the transition takes place, is about 0.25 eV below an excited cited 2 A 1 g state ( 2 A ∗ 1 g ), but that after relaxation the 2 A ∗ 1 g state is lowest in energy, making emission to the ground state partially forbidden.