Photoluminescence spectra and lifetimes of \({{}^4\hbox{I}_{{13}/2} \rightarrow {}^4\hbox{I}_{{15}/2} }\) and \({{}^4\hbox{I}_{{11}/2} \rightarrow {}^4\hbox{I}_{{15}/2} }\) transitions in erbium doped GeGaSe and GeGaS glasses

Article

DOI: 10.1007/s10854-007-9189-5

Cite this article as:
Koughia, K., Munzar, M., Aoki, T. et al. J Mater Sci: Mater Electron (2007) 18(Suppl 1): 153. doi:10.1007/s10854-007-9189-5

Abstract

The steady-state and transient photoluminescence has been investigated in Ge-Ga-Se and Ge-Ga-S chalcogenide glasses with stoichiometric composition and heavily doped with Er. These glasses show the expected characteristics of \({\hbox{Er}^{3+}}\) ion absorption/emission bands. The Judd-Ofelt analysis yields radiative lifetimes of the \({{}^{4}\hbox{I}_{13/2}\rightarrow ^{4}\hbox{I}_{15/2 }}\) transition, \({\tau_{JO} }\). We find \({\tau_{JO} \approx1.8}\)  ms for GeGaSe:Er, and \({\tau_{JO} \approx 2.6}\)  ms for GeGaS:Er. However, we find that the PL decay after the interruption of excitation shows a characteristic decay time \({\tau_D }\) which is substantially longer than the theoretically predicted \({\tau_{JO} }\) . In the present paper we discuss an energy transfer model which is based on the assumption that the excitation can travel along the system of isolated \({\hbox{Er}^{3+}}\) ions with negligible self-quenching due to successive absorption–emission events caused by optical transitions between \({{}^{4}\hbox{I}_{15/2}}\) and \({{}^{4}\hbox{I}_{13/2 }}\) levels (and vice versa) in \({\hbox{Er}^{3+}}\) ions. We show that the model can effectively explain the experimental data and we make the conclusion that \({\hbox{Er}^{3+}}\) ions in GeGaSe glasses with stoichiometric compositions and high concentration of Ga reside in isolated states and have a negligible rate of non-radiative relaxation from \({{}^{4}\hbox{I}_{13/2 }}\) to \({{}^{4}\hbox{I}_{15/2}}\) and levels.

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© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Electrical and Computer Engineering DepartmentUniversity of SaskatchewanSaskatoonCanada
  2. 2.Department of Electronics and Computer Engineering, Joint Research Center of High-technologyTokyo Polytechnic UniversityAtsugiJapan

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