On the Spectral Intensity Distribution of Donor–Acceptor Pair Recombination in GaP

The spectral intensity distribution of donor–acceptor pair spectra in GaP (donors at P sites) is theoretically investigated by use of a model recently developed for the evaluation of photon energies, and is compared with experimental data. For high excitation levels the intensity distribution is governed by the overlap integral of electron and hole wave functions and is found to depend on the impurity concentration, but hardly on the chemical nature of the impurities involved, i.e. not on the central cell correction. The implications of these observations are discussed.