Vacancy-migration-mediated disordering in CuPt-ordered (Ga,In)P studied by in situ optical spectroscopy in a transmission electron microscope

摘要

We examined electron-irradiation-induced disordering in CuPt-ordered (Ga,In)P by in situ photoluminescence and cathodoluminescence spectroscopy in a transmission electron microscope. A decrease of luminescence intensity following an electron irradiation in the energy range above 120 keV has been observed. We have shown that the decrease is due to the Frenkel-type defects on the Ca and In sublattices generated by electron irradiation, and the threshold electron energies for the displacement of Ga and In atoms have been estimated to be 145 and 120 keV, respectively. We propose that (1) electron-irradiation-induced migration of group-UI (Ga and In) vacancies dominates the disordering in the dose range below 2 x 10(20) cm(-2), and (2) spontaneous recombination of group-III vacancies and interstitials dominates the disordering in the dose range above 5 x 10(21) cm(-2). [S0163-1829 (99)03904-1]. [References: 29]