Elena Gnani

 Bachelor's Thesis - Investigation of Different Methods for Solving the Poisson Equation in Transistors Made of Two-Dimensional Materials

Electrostatics is a crucial aspect of studying electronic devices; when combined with other methods derived from quantum mechanics, it allows for accurate current calculations. In this context, the Poisson equation is a fundamental tool for determining the behavior of the electrostatic potential. This second-order differential equation can be solved using various methods (finite element method, finite difference method, etc.). The candidate is expected to study and implement one of the methods proposed in the literature for solving the Poisson equation and apply it to the DS-FET, a two-dimensional transistor with ultra-low power consumption.

Bachelor's Thesis - Quantum Charge Transport in Cold-Source Transistors

In nanometer-scale transistors, semiclassical methods for charge transport fail to accurately predict current behavior due to the reduced number of scattering events as device dimensions shrink. For this reason, alternative transport models are introduced to provide more accurate current descriptions. The candidate is required to study and apply one such method to transistors made of two-dimensional materials (e.g., graphene, single-layer molybdenum disulfide). These materials are key components in so-called "cold-source" devices, known for their high energy efficiency.

Master's Thesis - Study of Dirac-Source FETs

By interposing a material with a linear E(k) dispersion relation between the source contact and the channel, the Dirac-source FET (DS-FET) surpasses the Boltzmann limit at room temperature, achieving subthreshold swings lower than 60 mV/dec. Studying these devices involves various challenges at different levels of abstraction. Within a "multiscale" simulation setup, ranging from quantum NEGF to TCAD and mixed device-circuit models, the candidate will select an area to focus on and advance the state of the art.

Master's Thesis - Ab-Initio Simulations of Van der Waals Junctions

Van der Waals junctions play a fundamental role in two-dimensional Dirac-source transistors, preventing carrier "thermalization" at the interface between source and channel materials. The candidate is required to develop an ab-initio simulation setup for the vdW junction and related structures.

Bachelor's and Master's Theses in Collaboration with CNR Bologna

These topics are suitable for both bachelor's and master's theses, differing in complexity and/or the quantity of measurements to be performed and interpreted.

• Activities: Current-voltage (I-V) and/or capacitance-voltage (C-V) measurements as a function of temperature on silicon carbide electronic devices.
• Devices: Bipolar diodes, unipolar diodes, Hall bars, MOSFETs, van der Pauw devices, transmission line geometry devices.
• Objective: Characterize the fabrication processes of the devices.
• Workstations: A parametric system for I-V and C-V characterizations at the wafer level (probe stations on the 2nd floor) and a Hall effect measurement system.
• Required Skills: Knowledge of semiconductor electronic devices, use of multimeters and their manuals, familiarity with LabVIEW could be advantageous for building new measurement setups or implementing measurement processes.