The low-temperature properties of the excitation-dependent photoluminescence emission, in nominally undoped n-type GaxIn1−x As (0.44≤x≤0.48) layers grown on InP by molecular-beam epitaxy, are investigated with changes of temperature and excitation intensity. The excitation-dependent emission is attributed to the quasi-donor-acceptor pair transition in impure compensated crystals. The random impurity potential arising from residual impurities causes a larger energy shift than expected for the usual donor-acceptor pair transition.