AsGaantisites and their relation to EL2 defects in GaAs

Photoquenching experiments of the magnetic circular dichroism and optically detected ESR and ENDOR signals of the As-antisite in various semi-insulating GaAs materials show that the isolated As Ga defects cannot be identified with the EL2 defect in either charge state. Investigations of the spin-lattice relaxation time T 1 in conventional ESR and ODESR experiments show that the As Ga defects seen in conventional ESR are not isolated As Ga centres but most probably complexes of As Ga defects. Therefore the correlations established previously between EL2 and As Ga defects from conventional ESR experiments must be reinterpreted to be correlations between EL2 defects and complexes of As Ga defects.