The internal radiative efficiency and the mechanism of temperature quenching of the 1.03, 1.20, and 1.30 eV emission bands in n-GaAs

A temperature independent non-radiative electronic transition is found in the donoracceptor pair recombination which gives rise to the 1.03, 1.20, and 1.30 eV emission bands in n-GaAs. As a result the internal quantum radiative efficiency of the 1.03, 1.20, and 1.30 eV emission bands in n-GaAs is lower than unity, so usually only a small part of carriers recombining via pairs studied emit photons. The dominant factor which accounts for a low radiative efficiency is a non-radiative three centre Auger process. As the probability of non-radiative transitions is temperature independent they cannot explain the observed temperature quenching of the 1.03, 1.20, and 1.30eV emission bands. The latter is connected with the decrease in the number of charge carriers recombining via pairs as a result of a thermal release of trapped carriers from the energy levels of donor-acceptor pairs.