ABSTRACT
InAs1-xSbx alloys grown by MBE and MOCVD are found to have reduced emission energies due to CuPt-type order, even for Sb concentrations as low as x = 0.07 (ΔE = 25-65 meV). Cross-section TEM examination of such alloys shows the two {111}B variants are separated into regions 1-2 pm across with platelet domains 10-40 nm thick on habit planes tilted ∼30° from the (001) growth surface. Nomarski optical images show a cross-hatched surface pattern expected for lattice-mismatched layers. The local tilt of the surface correlates with the dominant variant in each region. InAs1-xSbx /In1-yGayAs strained-layer superlattices with low Sb content and flat surfaces also show CuPt ordering.
