AN INVESTIGATION BY RESISTANCE AND PHOTOLUMINESCENCE MEASUREMENTS OF HIGH-ENERGY HEAVY-ION IRRADIATED GAAS

Silicon-doped (n-type) GaAs samples were irradiated at GANIL with oxygen, krypton. argon and xenon ions at energies of about 0.2, 0.4, 1.4 and 5.5 GeV, respectively. Resistance measurements were performed at 300 K, in situ, as a function of fluence. The results show an irreversible increase of the resistivity, probably due to the creation of deep-level traps. The comparison of the experimental and theoretical (nuclear collisions) defect production rates suggests a slight effect due to electron excitation. Photoluminescence experiments were carried out at 4 K for silicon-doped (n-type) and zinc-doped (p-type) GaAs, which had been irradiated by 0.3 GeV calcium and 0.7 GeV zinc ions at various fluences. The photoluminescence signal decreases with increasing fluence. The decrease of the donor-acceptor transition line is much more rapid for p-type than for n-type GaAs, which suggests different defect creation mechanisms.