Donor-Acceptor Pair Recombination Spectra in Cadmium Sulfide Crystals

Abstract

Discrete donor-acceptor pair lines converging to the 5163 Å broad green peak are reported. The lines are characterized in zero magnetic field by spin-exchange splitting which decreases with increasing pair separation. Some of the lines also show zero-magnetic-field splitting due to crystal-field effects. A set of closely spaced lines converging at 2.518 eV is also reported. This set of lines can be interpreted as donor-acceptor pair lines in which the recombination goes to an excited state of the acceptor. A good theoretical fit to the energy profile of the pair lines was not achieved. The density of pair lines can be accounted for by a single donor and acceptor.