Radiative transitions associated with two-acceptor—one-donor complexes in epitaxial GaAs and InP

Abstract

Radiative transitions on the low-energy side of the exciton—neutral-acceptor transitions are reported in good-quality epitaxially grown samples of GaAs and InP at liquid-helium temperature. These lines result from transitions within a complex involving two shallow neutral acceptors and a single neutral donor. The initial state of the system consists of two neutral acceptors each with an exciton bound to it, and a neutral donor. The exciton collapses on one of the acceptors, giving part of its radiative energy to the second acceptor-exciton system to transfer the exciton to the neutral donor. The final state, therefore, consists of two neutral acceptors and a neutral-donor-bound-exciton system. The transition energies predicted on the basis of this model agree very well with the observed energies in both GaAs and InP.