Charge confinement in $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}$ self-assembled quantum wires is studied experimentally using photoluminescence in pulsed magnetic fields and theoretically using adiabatic theory within the effective-mass approximation, taking into account the strain in the samples. We show both experimentally and theoretically that, in spite of the large conduction band offset, the electron wave function is significantly spilled out of the wire in the wire height direction for thin wires. Furthermore, for a wire thickness of up to 8 monolayers, the electron spillover is inversely related to the wire height. These effects are due to the large zero point energy of the electron. As the wire becomes thicker, the decrease in confinement energy is reflected in a reduction of the electron wave-function extent.

We present a study of the structural and optical properties of InAs quantum dots formed in a low density template of nanoholes fabricated by droplet epitaxy on GaAs (001). The growth conditions used here promote the formation of isolated quantum dots only inside the templated nanoholes. Due to the good optical quality and low density of these nanostructures, their ensemble and individual emission properties could be investigated and related to the particular growth method employed and the quantum dot morphology.

The size and emission wavelength of self-assembled $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}\left(001\right)$ quantum wires (QWrs) is affected by the $\mathrm{P}∕\mathrm{As}$ exchange process. In this work, we demonstrate by in situ stress measurements that $\mathrm{P}∕\mathrm{As}$ exchange at the $\mathrm{In}\mathrm{As}∕\mathrm{In}\mathrm{P}$ interface depends on the surface reconstruction of the InAs starting surface and its immediate evolution when the arsenic cell is closed. Accordingly, the amount of InP grown on InAs by $\mathrm{P}∕\mathrm{As}$ exchange increases with substrate temperature in a steplike way. These results allow us to engineer the size of the QWr for emission at 1.3 and $1.55\mu \mathrm{m}$ at room temperature by selecting the range of substrate temperatures in which the InP cap layer is grown.