Photoluminescence studies have been performed on undoped and silicon‐doped GaAs crystals, which were annealed between 650 and 1000 °C under different arsenic pressures. Samples were also heat treated with the addition of pure elemental Ga, Mn, or Cu. Spectra were taken in the energy range 1.15–1.55 eV at the surfaces of the annealed crystals and at various depths below the surface. Newly observed zero‐phonon emissions at 1.31 and 1.347 eV are concluded to be related to CuGa‐(VAs)2and CuGa‐VAs, respectively. An emission at 1.467 eV also was found to be related to a CuGa‐containing complex. A new emission at 1.342 eV was found to be related to a fast diffusing MnGa‐containing complex. Most likely, the emission originates from a MnAscenter. The nature of these defects is discussed on the basis of their emission characteristics, diffusion behavior, and dependence on annealing parameters. Through this study it appeared that arsenic vacancies play a crucial role both in the establishment of defect equilibria and in the formation of complexes with MnGaand CuGa. A new luminescence peak at 1.448 eV was found to be related to theVAsdefect. Most probably, it has to be associated with the GaAsantisite. The presence of arsenic vacancies also induces a shift of the 1.492‐eV emission to 1.484 eV. This shift is attributed to the replacement of CAsby SiAsacceptors. Some evidence was found that a peak at 1.38 eV is associated withVGa. It is concluded that solid‐state equilibrium of native defects and impurities is only established at the surfaces but not in the bulk of the crystal during the heat treatments.