Strain-compensated GaAs_1−yP_y/GaAs_1−zBi_z/GaAs_1−yP_y quantum wells for laser applications

GaAs_1−zBi_z/GaAs_1−yP_y strained-compensated quantum well (QW) structures for laser applications were grown by metalorganic vapor phase epitaxy. The band offsets for the GaAs_1−zBi_z/GaAs_1−yP_y heterojunction were calculated by the density functional theory, and the design of strain-compensated structures was undertaken by the zero stress analysis. The post-growth thermal annealing of the structures dramatically increases the photoluminescence intensity compared to that from as-grown GaAs_1−zBi_z QW samples. Transmission electron microscopy studies verified layer thicknesses as well as the presence of abrupt interfaces in the annealed GaAs_1−zBi_z/GaAs_1−yP_y QW structure. Electroluminescence measurements from ridge-waveguide devices show broad spectral emission characteristics and lasing was not observed up to a current injection of 4 kA cm⁻². (paper)