Erbium complexes and defect levels in MBE-grown erbium-doped GaAs and AlGaAs

Abstract Erbium doped GaAs and AlGaAs layers were grown using MBE at various Er concentrations. Low temperature photoluminescence (PL) measurements indicate that the most intense Er emissions occur near [Er]=10 19 cm -3 and fall off sharply by [ Er ] = 6×10 19 cm -3 . PL and lifetime measurements indicate that there are at least 3 distinct optically active centers. Electrical measurements show that Er-related hole traps in GaAs are at 35, 150, and 340 meV above the valence band.