Temperature dependence of atomic ordering and composition modulation in InAsSbBi grown by molecular beam epitaxy on GaSb substrates

The structural and optical properties of two 210 nm thick InAsSbBi epilayers grown on (100) GaSb substrates by molecular beam epitaxy at 400 and 280 degrees C are investigated using X-ray diffraction, Rutherford backscattering spectroscopy, transmission electron microscopy, and photoluminescence spectroscopy. Both samples are free of observable defects. The higher temperature growth results in reduced Bi incorporation, good optical performance, smooth interfaces, and lateral composition modulation of the Bi mole fraction. The lower temperature growth results in near unity Bi incorporation, poor optical performance, interface roughness, and CuPtB -type atomic ordering on the {111}B planes. (C) 2020 Elsevier B.V. All rights reserved.