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Absorption and luminescence due to excitons bound to neutral acceptors in GaP

1970; Elsevier BV; Volume: 3; Issue: 3 Linguagem: Inglês

10.1016/0022-2313(71)90059-7

1872-7883

A.T. Vink, Robert C. Peters,

GaN-based semiconductor devices and materials

Low temperature absorption and luminescence spectra due to excitons bound to neutral acceptors C, Zn and Cd in GaP are reported in this paper. Most measurements were performed on GaP crystals grown epitaxially on GaP substrates by the H2/HCl or the H2/H2O method. Several zero-phonon (ZP) transitions, each with strong replicas of momentum conserving (MC) phonons were observed in both absorption and luminescence. For the lowest energy transition of excitons bound to neutral acceptors—and also donors—the exciton binding energy and the strenght of the ZP transitions, relative to their phonon replicas, are discussed with respect to the ionization energy of the centre involved. The intrinsic radiative lifetime calculated from absorption is significantly larger than the experimentally found upper limit, showing that a non-radiative parallel process must exist, as is the case for excitons bound to neutral donors. The spectra are also discussed in relation to the methods of crystal growth.