Pressure dependence of the photoluminescence spectra of nitrogen-doped ZnSe: Evidence of compensating deep donors

Abstract

We have measured the photoluminescence spectra of nitrogen-doped ZnSe under hydrostatic pressure. From the pressure dependence of the peak positions of the acceptor-bound exciton and donor-acceptor-pair emissions, we show that highly doped samples have two donor-acceptor-pair transitions, one involving shallow and one involving deep donors. Our results confirm that one mechanism limiting the free hole concentration is compensation from this deep donor.