Influence of fast-neutron irradiation on the intensity of the copper-related luminescence band at h nu(m)=1.01 eV in n-type GaAs

The influence of neutron irradiation (the energy E = 2 MeV and the dose Phi = 10(13)-10(15)cm(-2)) and subsequent anneals (the annealing temperature T-a = 400-700 degrees C and the annealing time is 30 min) of n-type GaAs(Te,Cu) crystals with an initial carrier concentration n(0) = 2 X 10(18) cm(-3) on the intensity of the copper-related luminescence band with an emission cm maximum at h nu(m) = 1.01 eV is studied. A significant irradiation-induced increase in the intensity of the band is observed. It is attributed to a radiation-stimulated increase in the concentration of emitting centers (CuGaVAs pairs) as a result of the effective interaction of interstitial copper atoms with irradiation-induced gallium (V-Ga) and arsenic (V-As) vacancies, as well as VGaVAs divacancies. (C) 1997 American Institute of Physics. [S1063-7826(97)00510-3].