IRON IMPURITIES AS NON-RADIATIVE RECOMBINATION CENTERS IN CHALCOGENIDE GLASSES

Photoluminescence and E.S.R. studies have been carried out on pure and iron-doped As2S3 glass. The luminescence spectra, photoluminescence excitation spectra, temperature dependence of the luminescence efficiency, and luminescence fatiguing curves demonstrate that the iron impurities quench the luminescence efficiency by introducing competing non-radiative recombination centres. The E.S.R. measurements reveal that iron is a pervasive inadvertent impurity even in nominally pure chalcogenide glasses. It is suggested that non-radiative recombination occurs by transfer of an exciton’s recombination energy to localized d-band excited states of an iron ion; the excited iron ion then relaxes non-radiatively by phonon emission. © 1979 Taylor & Francis Ltd.