An ODMR study of close donor-acceptor pair recombination involving Cu and Li complexes in GaP

Abstract

The authors have observed ODMR signals in (Cu-Li) doped GaP, resulting from the recombination between electron-hole pairs localised at donor-acceptor pair-like complexes with varying separations. The resonances change in appearance with detection wavelength or modulation frequency from a triplet exciton spectrum, which corresponds to a strongly coupled pair, to a single resonance at the mean g-value of the electron and hole g-value for weakly coupled pairs. The ODMR data are discussed in relation to a defect model with a trigonal (CuGa - Lii) acceptor-like part, and a single interstitial donor-like part at varying distance.