Surface effects on shape, self-organization and photoluminescence of InAs islands grown on InAlAs/InP(001)

InAs nanostructures were grown on ${\mathrm{In}}_{\text{0.52}}{\mathrm{Al}}_{\text{0.48}}\mathrm{As}$ alloy lattice matched on InP(001) substrates by molecular beam epitaxy using specific growth parameters in order to improve island self-organization. We show how the change in InAs surface reconstruction via growth temperature from $\text{(2×4)}$ to $\text{(2×1)}$ and/or the use of InAlAs initial buffer surface treatments improve the island shape homogeneity (either as quantum wires or as quantum dots). Differences in island shape and in carrier confinement are shown by atomic force microscopy and by photoluminescence measurements, respectively. We point out that such shape amendments induce drastic improvements to island size distribution and discernible changes in photoluminescence properties, in particular concerning polarization.