Molecular Beam Epitaxy Growth and Photoluminescence of Type-II (GaAs_1-xSb_x/In_yGa_1-yAs)/GaAs Bilayer Quantum Well

We report a systematical study on the molecular beam epitaxy growth and optical property of (GaAs_1-xSb_x/In_y Ga_1-yAs)/GaAs bilayer quantum well (BQW) structures. It is shown that the growth temperature of the wells and the sequence of layer growth have significant influence on the interface quality and the subsequent photoluminescence (PL) spectra. Under optimized growth conditions, three high-quality (GaAsSb_0.29/In_0.4GaAs)/GaAs BQWs are successfully fabricated and a room temperature PL at 1314nm is observed. The transition mechanism in the BQW is also discussed by photoluminescence and photoreflectance measurements. The results confirm experimentally a type-II band alignment of the interface between the GaAsSb and InGaAs layers.