Improving photoluminescence of highly strained 1.32 μm GaAsSb/GaAs multiple quantum wells grown on misorientation substrate

The (1 0 0) GaAs substrates with misorientations of 0°, 2°, 6°, and 15° toward [0 1 1] were used in this study to improve the crystal quality and optical properties of GaAsSb/GaAs quantum wells (QWs) grown by metalorganic vapor phase epitaxy (MOVPE). The 15° off sample possesses the lowest Sb content of the GaAsSb epi-layer, which thereby means the epitaxy has smaller Sb distribution coefficient. The comparison of photoluminescence (PL) spectra also exhibit that the 15° off sample is with stronger PL intensity and without peak shifting and spectral width broadening. These phenomena show that the crystal quality has been greatly improved by growing GaAsSb/GaAs QW structures on misorientation substrates.