We report time‐resolved luminescence data on the 155‐eV band of Ge‐doped AlxGa1−xAs withx=0.3, grown by liquid‐phase epitaxy. They are interpreted in terms of donor‐acceptor pair recombinations in which the donors and acceptors have a well‐defined spatial separation. From the analysis of the emission line shape, the optical parameters of the pair are deduced.