ANALYSIS OF TIME-RESOLVED DONOR-ACCEPTOR-PAIR SPECTRA OF ZNSE-LI AND ZNSE-N

We measured the time-resolved photoluminescence of ZnSe:Li bulk crysta ls and ZnSe:N heteroepitaxial layers in the donor-acceptor-pair (DAP) transition region. We found nonexponential decay curves for all sample s and all spectral positions except for luminescence from nearest DAPs . It is shown that the approach by Thomas et al. perfectly describes t his overall behaviour for ZnSe:Li as well as for ZnSe:N if, for the la tter, transitions from the deep donor to the shallow nitrogen acceptor are considered. Our fit of the decay curves yields a binding energy o f (50 +/- 2) meV for the deep nitrogen-related donor with an effective Bohr radius of(22.8 +/- 0.6) Angstrom. (C) 1998 Elsevier Science B.V. All rights reserved.