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We report on the crystal morphology and Raman scattering features of high structural quality GaSb1−xBix alloys grown by molecular beam epitaxy with a high Bi content (x up to ∼0.10). The Raman spectra were measured at room temperature with different laser excitation wavelengths of 532 nm, 633 nm, and 785 nm. We observed well-defined Bi-induced Raman peaks associated with atomic Bin clusters and GaBi vibrational modes. Remarkably, some Bi-induced Raman modes were strongly enhanced when the laser energy was selected near an optical transition for the 5.8%Bi sample. This effect was attributed to a Raman resonant effect near an excited optical transition of the GaSbBi layer and has been used to identify the nature of the observed Raman peaks. [ABSTRACT FROM AUTHOR]

Optical properties of diluted magnetic semiconductor Ga0.999Mn0.001As/AlAs quantum well structures grown on (1 0 0 ), (1 1 0), (3 1 1)B and (4 1 1)B by molecular beam epitaxy are reported. Temperature-dependent spectral photoluminescence (PL) measurement was performed at temperatures between 15 and 300 K. The PL measurements showed that band gap of the alloy decreases with increasing lattice temperature regardless the growth orientations. S-shaped temperature dependence has been observed in the samples grown on (1 0 0), (3 1 1)B, (4 1 1)B orientations. PL emission energy is fitted with Varshni and Bose–Einstein Approximation to determine Debye temperature (β), (ΘE) and thermal expansion coefficient (α), the exciton–phonon coupling strength (aB). [ABSTRACT FROM AUTHOR]

Highlights: [•] Photoluminescence intensity enhancement has been observed for annealed GaAsBi samples. [•] Red shift of 40meV was observed for the annealed sample. [•] Annealing reduces the defects inside the GaAsBi layers. [ABSTRACT FROM AUTHOR]