LUMINESCENCE AND FLUORESCENCE LINE NARROWING STUDIES OF CHROMIUM DOPED GLASS

The technique of fluorescence line narrowing is applied to the 2E - 4A2 transition on Cr3+ ions in ED-2 glass. The resultant sharp zero-phonon line is accompanied by a vibrational sideband which carries information about the range of vibrational modes of the glass. The homogeneous broadening of the zero-phonon line is measured as a function of temperature

Temperature dependent spectroscopic studies of the electron delocalization dynamics of excited Ce ions in the wide band gap insulator, Lu2SiO5

Electron delocalization processes of optically excited states of Ce3+ impurities in Lu2SiO5 were investigated by means of a temperature and spectrally resolved photoconductivity study. By monitoring separately the strength of the photocurrent resulting from excitation into each of the Ce3+?5d absorption bands, over a broad temperature region, three different delocalization processes, namely direct photoionization, thermal ionization, and tunneling, have been identified. The relative probabilities and temperature dependencies of each of these processes are discussed. The observed exponential temperature increase in the photocurrent, which spans six orders of magnitude, allows for the exact placement of the lowest energy 5d levels of the Ce3+ ions within the band gap. For Lu2SiO5:Ce3+, the lowest 5d state is determined to be 0.45 eV below the conduction band edge.Radiation, Radionuclides and ReactorsApplied Science