ETD

• 2-dimensional materials
• computational nanoelectronics
• graphene
• heterostructures
• materials science
• nanomagnets
• negf
• quantum cascade detector
• spintronics
• wannier functions

The thesis work consisted in applying a state-of-the art computational approach to the modelling and simulation of different electronic devices based on 2-dimensional materials.
The Multi-Scale method, comprising density functional theory calculations, Hamiltonian wannierization and ballistic or semi-classical electronic transport simulations, enables a thorough and accurate study of current flow in a device.
This methodology was first applied to the analysis of transmission across multiple 2-dimensional materials-based vertical homo- and heterostructures, considering different stacking orientations and flake overlaps; it was then used to model and simulate a combined spin filter and transistor device based on the CrI3 nanomagnet, where an external electric, instead of magnetic, field enables the spin selection; then, I modelled and simulated a 2-dimensional materials-based field-effect transistor used as a reader for a quantum cascade detector, examining different channel materials and computing the responsivity. Subsequently, I worked on reproducing experimental I-V curves referred to ultrashort channel graphene field effect transistors to be used for radio-frequency applications; finally, I elaborated a method to reduce the size of the Wannier Hamiltonian in order to speed up transport simulations.