Résumé
Nitride semiconductors have been at the center of semiconductor research in the last decade. However Indium nitride is still poorly known, due to its growth difficulty, and its properties are still the subject of passionate debates. Still, it is clear that it is a very promising material for telecommunication optoelectronics and hyperfrequency/terahertz applications. In particular, nanostructures based on InN are extremely interesting, by combining a small bandgap, the incredible efficiency of nitride semiconductors and the tunability of quantum dots. In this paper, we present the latest advances in the growth and optical properties of InN quantum dots grown onto GaN. The optical properties of InN dots will be compared to those of InN films, and we will show that the thermal behaviour of InN dots is far superior. Using TEM and synchrotron radiation diffraction, we will analyze the strain state of the dots at the nanometer scale, along the growth axis of the dots. These results, combined with the thermodynamical analysis of the growth data, will allow us to demonstrate that the growth mechanism is not the usual Stransky-Krastanow mode, but is more related to the BCF (Burton-Cabrera-Franck) model.