ETD system

Electronic theses and dissertations repository


Tesi etd-06222020-093913

Thesis type
Tesi di dottorato di ricerca
Multi-scale modeling of 2D-material based devices
Settore scientifico disciplinare
Corso di studi
tutor Prof. Fiori, Gianluca
relatore Prof. Iannaccone, Giuseppe
Parole chiave
  • lateral heterostructures
  • printable electronics
  • network
  • carbon nanotube
  • electronic transport
  • electronic devices
  • 2D materials
  • multi-scale modeling
Data inizio appello
Riassunto analitico
In this thesis, we provide insights for the fabrication of new devices through the multi-scale simulation method. We first examine the ultimate performance of MoS2-channel FETs with a gate length of 1 nm for uniformly scaled devices with channel lengths in the nm range, as would be required in integrated circuits. We also evaluate the effect of the finite density of states of a carbon nanotube gate on the loss of device performance. Secondly, we investigate the possibility of reducing the metal-semiconductor contact resistance by building lateral heterostructure (LHs) based on noble transition metal dichalcogenides. We show that in the case of PdS2 it is possible to achieve sub-60 mV/decade subthreshold swing thanks to energy-filtering mechanisms due to a particular source density of states. Besides, we predict the possibility of using 2D LHs to obtain a resonant tunneling diode, with a pronounced peak-to-valley ratio of the current-voltage characteristics. Finally, we describe a drift-diffusion based method to study electronic transport in inkjet-printed 2D material networks. We obtain the in-plane and out-of-plane mobility values from ab initio simulations and solving a self-consistent algorithm we obtain the output and
transfer characteristic for the structures defined. Through statistical studies, we find
the variability in mobility and sheet resistance as a function of the flake density.