Computation of Phonon Bandstructure in III-V Nanostructures
Phonons or crystal oscillations play a very important role in nanostructures since they determine their thermal conductivity. If phonons can propagate efficiently through a material, its thermal conductivity will be high, which is good for applications where heat must dissipate rapidly such as transistors. On the contrary, in a structure with a disturbed phonon propagation, the thermal conductivity is reduced, offering the possibility to create good thermogenerators. The goal of this project is to calculate the bandstructure of phonons confined in quantum wells and nanowires using the valence-force-field (VFF) method in order to get a new insight into thermal transport in nanostructures. This was already done for group IV semiconductors as shown here for Si, but the model still needs to be extended to III-V semiconductors (GaAs, InP, AlN, ...), for which there is an additional Coulomb interaction term between the ions. While this long-range term can be treated using Ewald's summation method in bulk structures, it is not clear how to handle it in nanostructures without too much increasing the computational burden.
- Looking for 1 Semester student
- Contact: Reto Rhyner
- Experience with matlab and basic knowledge in bandstructure calculation
- 30% Theory
- 60% Implementation
- 10% Model verification