Abstract
Changes in photoluminescence intensities, energies, and band shapes as a function of temperature in the range 4.2–300 K lead to the identification of germanium as a 40 ± 2 meV deep acceptor in GaAs. Luminescence due to this acceptor quenches near 200 K in favor of a high‐energy band that grows out of the low‐temperature bound and free‐exciton structure. The origin of the 300 K luminescence is considered and it is attributed to band‐to‐band recombination.