Suppression of the free-to-bound luminescence by EL2

Abstract Liquid phase epitaxial GaAs layers have been subjected to 2 MeV electron irradiation and examined by low temperature luminescence measurements during subsequent annealing. From the free-to-bound transition (e,A O ) it can be concluded that acceptors substitute for arsenic sites are suppressed compared to those occupying gallium sites. It is suggested that As-site acceptors are captured by As Ga −V As defects (believed to be responsible for EL2) and thereby the electronic level of the nearest neighbour impurity is passivated by the double donor antisite As Ga .