Excitation spectroscopy on donor-acceptor pair luminescence in GaP

Abstract
Luminescence excitation experiments on donor-acceptor pairs in GaP are reported. Using different combinations of deep donor and shallow acceptor, we determine the unperturbed excited states of the acceptors C, Mg, Zn, and Cd as well as their dependence on the pair separation. The assignment of the states is discussed in detail. Good agreement has been found with results from ir absorption and Raman scattering.