Incorporation of erbium in GaAs by liquid-phase epitaxy

Abstract

The incorporation of the lanthanide element erbium in GaAs during growth by liquid-phase epitaxy is investigated by low-temperature photoluminescence measurements. After an anneal of the epitaxial layers at 850 °C, a characteristic Er-associated optical transition appears at a wavelength of ∼1.55 μm, however, no erbium-related photoluminescence signal is found in the as-grown GaAs:Er layers. The Zeeman splitting of the new photoluminescence lines reveals a cubic symmetry of the optically active Er complex. Successive mechanical polishing and annealing of the layers provides evidence for the incorporation of Er within the layer as an optically inactive Er complex, which is activated only at the surface by thermal annealing.