Compound semiconductors provide a high flexibility in band structure engineering and cover a wide spectral band, meeting requirements for a large amount of optoelectronic applications. Moreover, they can be structured as quantum wells or quantum dots to form efficient emitters for laser diodes. My thesis deals with the development of novel quantum heterostructures for GaAs technology with the aim to further extend this material system range of applications. I have investigated two kinds of nanostructures: growth on nanostructured surfaces and GaAsBi alloys. The first part of the work is dedicated to the molecular beam epitaxy of InGaAs quantum wells and InAs quantum dots on nanopatterned GaAs surfaces. Surface patterning was carried out using a nanoimprint lithography process that we have developed and by electron beam lithography. Critical to the success of the subsequent growth step was the development and optimisation of hydrogen plasma and Ga-triggered oxide desorption from patterned GaAs to obtain smooth and clean surfaces. Our results show that growth of quantum dots can be directed, with dependence in orientation and pattern size. Furthermore, photoluminescence from these nanostructures is observed at room temperature. In the second part of the thesis, the growth of GaAsBi quantum wells was studied after optimization of the growth conditions for thick GaAsBi layers. Room temperature emission up to a wavelength of 1.22 μm is demonstrated for a strained GaAsBi quantum well (7% Bi). This latter structure exhibits flat interfaces. Moreover, the presence of defect-related localized states was highlighted by photoluminescence spectroscopy. It is further shown that these defects cannot be entirely suppressed by a rapid thermal annealing treatment.
