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.

COMPUTATIONAL DEVICE MODELING BASED ON 2-DIMENSIONAL MATERIALS

CANNAVO', EMMANUELE
2024

Abstract

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.
26-mar-2024
Italiano
2-dimensional materials
computational nanoelectronics
graphene
heterostructures
materials science
nanomagnets
negf
quantum cascade detector
spintronics
wannier functions
Fiori, Gianluca
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14242/216430
Il codice NBN di questa tesi è URN:NBN:IT:UNIPI-216430