High material quality growth of AlInAsSb thin films on GaSb substrate by molecular beam epitaxy

In this paper, high material quality Al_0.4In_0.6AsSb quaternary alloy on GaSb substrates is demonstrated. The quality of these epilayers is assessed using a high-resolution x-ray diffraction, Fourier transform infrared (FTIR) spectrometer, and atomic force microscope (AFM). The x-ray diffraction exhibits high order satellite peaks with a measured period of 31.06 Å (theoretical value is 30.48 Å), the mismatch between the GaSb substrate and AlInAsSb achieves -162 arcsec, and the root-mean square (RMS) roughness for typical material growths has achieved around 1.6 Å over an area of 10 μm×10 μm. At room temperature, the photoluminescence (PL) spectrum shows a cutoff wavelength of 1.617 μm.