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Multiple quantum well (MQW) samples grown by the molecular beam epitaxy method were irradiated by alpha particles from isotope 239.Pu. The photoluminescence (PL) spectra and PL integrated intensity dependencies are presented at various alpha particle fluences, up to 10(exp 11) cm(exp -2). The experimental results are in agreement with a model which assumes that point centers (residual impurities and point defects introduced during irradiation) are responsible for PL intensity decrease with the alpha particle fluence. It was found that annealing of irradiated MQW samples at a temperature above 650 K nearly restores the PL intensity. An enhancement of PL by more than an order of magnitude was observed at annealing temperatures higher than 850 K, just before GaAs and Al(0.35)Ga(0.65)As interdiffusion begins.

Impact neutralization coefficient for the reaction D−+e→D0+2e is reported, where D− and D0 are the negatively charged and neutral donor, respectively, and e is the conduction band electron. The coefficient was calculated using the Boltzmann transport equation and the scaled neutralization cross section of the negatively charged hydrogen atom. At liquid helium and lower temperatures the above reaction for n-GaAs and n-InP doped with shallow donors was found to be characterized by a relatively large impact neutralization coefficient. At weak electric fields, from about 0.2 to 1 V/cm, the neutralization coefficient increases exponentially and at higher fields saturates at the value of about 1.5×10−3 cm3/s for n-GaAs and 9×10−4 cm3/s for n-InP.