Optical characteristics of erbium doped AlGaAs-GaAs heterostructures

Erbium (Er) doped AlGaAs-GaAs multiple quantum well heterostructures have been grown by molecular beam epitaxy and optically characterized using photoluminescence. It was found that the Er³⁺ luminescence of the MQW structures with Er doped GaAs quantum wells and undoped Al_xGa_1-xAs barriers was strongly dependent on the Al composition. This result suggests that the prolonged carrier lifetime in the barriers, where the X band is lower in energy than the Γ band, improves the energy transfer from the host semiconductor to the Er³⁺ ions. Emission intensity versus excitation power measurements were also performed and data indicate that a high efficiency of energy transfer can be achieved by incorporating Er in MQW heterostructures