A Study of Electron Radiation Damage in GAAS, GAP, GAAS(1-X)p(X) Based on Recombination Radiation

摘要

The results of a study of electron bombardment induced radiation damage in GaAs, GaP and GaAs(1-x)P(x) single crystal based on monitoring the recombination radiation (cathodoluminescence spectrum) of these materials is presented. The electrons which produced the damage were supplied by a 450 keV Van de Graaff accelerator. Irradiations were performed at liquid nitrogen or liquid helium temperatures. The temperature dependence of the cathodoluminescence spectrum was established in n- and p-GaAs. The changes in the spectra resulting from exposure to electrons of sufficient energy to cause atomic displacements consisted only of reductions in the intensity of all lines in the pre-irradiation spectra, i.e. no new lines or bands associated with radiative transitions involving the centers introduced by the irradiation were found in any of the materials. The thresholds for damage, i.e. the minimum electron energy needed to bring about a detectable change in the intensity of emission under constant excitation conditions were determined. The degradation rates as a function of electron energy were compared to the Mott-McKinley-Feshbach formulation and were generally found to give good qualitative agreement. An estimate of the capture cross sections of the radiation defects was made. (Author)