The role of impurity bands and electron-phonon interaction in formation ofnear-band-edge PL spectra of compensated ZnSe

A modification of the potential fluctuation model is proposed to explain th e experimentally observed dependencies of the band shape and maximum positi on of the impurity luminescence in ZnSe samples highly doped with nitrogen on the doping level, excitation intensity, temperature, and decay time. In the proposed model, transitions from the localized and delocalized states o f the donor impurity band and the conduction band tail appearing at high-do ping level due to overlap of the wave functions of donor states, to the acc eptor levels are considered instead of the donor-acceptor pair recombinatio n. The influence of the electron-phonon interaction parameter on the spectr al shape was taken into account. (C) 2000 Published by Elsevier Science B.V , All rights reserved.