Impact of substrate temperature on the structural and optical properties of strain-balanced InAs/InAsSb type-II superlattices grown by molecular beam epitaxy

摘要

Molecular beam epitaxial growth of strain-balanced InAs/InAs1-xSbx type-II superlattices on GaSb substrates has been investigated for substrate temperatures from 400 °C to 450 °C. The Sb composition is found to vary linearly with substrate temperature at constant V/III ratios. For samples grown at the optimized substrate temperature (410 °C), superlattice zero-order peak full-width at half-maximums are routinely less than 25 arc sec using high-resolution X-ray diffraction. Cross-sectional transmission electron microscopy images show the absence of any visible defects. Strong photoluminescence covers a wavelength range from 5.5 to 13 μm at 12 K. Photoluminescence linewidth simulations show satisfactory agreement with experiments.