Nanostructured III-V epilayers on silicon substrate for optoelectronic applications

The integration of III-V devices on Si substrates would allow the fabrication of specialized devices for optoelectronics and photonics directly on the highly refined silicon infrastructure, based on CMOS technology. In this work of thesis, Droplet Epitaxy technique is used for the low thermal budget fabrication of GaAs quantum nanostructures on silicon substrates through a Ge layer and for the fabrication of GaAs local artificial substrates directly on Si substrate. Quantum nanostructures grown on Si substrate through a Ge layer showed an intense photoluminescence emission, detectable up to room temperature and with a ratio between number of photon emitted and photogenerated carriers similar to the one obtained for GaAs quantum nanostructures grown by droplet epitaxy on GaAs substrate. GaAs local artificial substrates fabricated on Si showed high tunability in size and density, a size dispersion below 10%, a good crystalline quality and well defined shapes with a high aspect ratio.