The Nitrogen Isoelectronic Trap in Phosphorus-Rich Gallium Arsenide Phosphide

The localization energy of excitons at N isoelectronic substituents in GaAsxP1−x has been determined from optical absorption spectra for x ≲ 0.2. The results indicate that the binding energy of the N-induced electron state associated with the X1 conduction band minima in GaAs may be relatively large, ∼0.08 eV. However, this state is still more than 0.3 eV above the lowest minimum at Γ1c. It is likely that there is no bound state associated directly with the Γ1 conduction band minimum.