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[[File:Simulation of the optical properties of nanostructured solar cells.png|320px|thumb]]
 
 
==Short Description==
 
==Short Description==
Nanostructures such as quantum wells, nanowires, or quantum dots are attracting a lot of attention as the active components of photovoltaic devices due to their improved energy conversion efficiency. To design them, it is important to precisely know where their conduction and valence band edges lie and how the resulting light absorption spectrum looks like. At the Integrated Systems Laboratory, we have recently developed a device simulator that allows one to construct nanostructures atom by atom and accurately calculate their optical properties. Presently, this modeling tool assumes that electrons and holes are captured within the simulation domain and cannot escape it. However, in reality, a current flows through the considered nanostructures, thus impacting the distribution of the electron and hole population. The goal of this project is to extend the existing simulation approach so that current flows can be taken into account in the calculation of the optical properties of solar cells.
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The project is aimed to provide the student the basic knowledge of Density Functional Theory (DFT) and Non Equilibrium Green's Function (NEFF) method. They represent the state-of-art of modeling for numerical simulations in vibrational,optical, and electronic properties and  transport properties of functional devices, respectively.To obtain accurate results and predict the characteristics of not-yet-fabricated structures, DFT and NEGF must be combined with each other, the former provides the Hamiltonian and Hessian matrices that the latter needs. The project will focus on thestudy of ballistic thermal properties of 2D Transition metal dichalcogenide (TMDs), such as MoS2.  The software involved in this project will be the DFT tool Quantum ESPRESSO and VASP as well as the device simulator OMEN.
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==The Big Picture ==
 +
Integrated electronics constitute one of the most important and spread aspects of our everyday life and among the years the size shrinking of transistors, the active component of all integrated circuits, has been supported and encouraged by several aspects. Obviously, in order to improve the performances of devices, the indefinitely reduction of dimensions  can not be the only prospective, but it must be combined with the research of new channel materials able to replace Silicon. Here, the quantum confinement plays a fundamental role, since it has been demonstrated that it significantly affects the properties of nano-sized materials with respect to their bulk counterparts. The simulations will focus on Transition Metal Dichalcogenide(TMDs), which  consist of one layer of a transition metal sandwiched between two chalcogen layers. Single-layers of TMD have received a wide attention following the the demonstration of a properly working MoS2 transistor. The final goal would be to found trends able to make the research more target-oriented and less hazarous.
  
 
===Status: Available ===
 
===Status: Available ===
: Looking for 1..2 Semester/Master student(s)
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: Looking for 1 Semester/Master studen
 
: Contact: [[:User:Mluisier | Mathieu Luisier]]
 
: Contact: [[:User:Mluisier | Mathieu Luisier]]
 +
 
===Prerequisites===
 
===Prerequisites===
: Interest in device physics
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We are seeking a candidate with a basic knowledge in solid state physics and quantum mechanics. Familiarity withprogramming language (python, c++) as well as ab-initio modeling are appreciated, but not necessary.
: Flair for computational modeling
 
: Experience with Matlab and/or C/C++ programming
 
 
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===Status: Completed ===
 
===Status: Completed ===
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===Character===
 
===Character===
 
: 40% Theory
 
: 40% Theory
: 40% Implementation
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: 40% Simulations
: 20% Testing
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: 20% Analysis
  
 
===Professor===
 
===Professor===

Revision as of 17:57, 3 September 2019

Short Description

The project is aimed to provide the student the basic knowledge of Density Functional Theory (DFT) and Non Equilibrium Green's Function (NEFF) method. They represent the state-of-art of modeling for numerical simulations in vibrational,optical, and electronic properties and transport properties of functional devices, respectively.To obtain accurate results and predict the characteristics of not-yet-fabricated structures, DFT and NEGF must be combined with each other, the former provides the Hamiltonian and Hessian matrices that the latter needs. The project will focus on thestudy of ballistic thermal properties of 2D Transition metal dichalcogenide (TMDs), such as MoS2. The software involved in this project will be the DFT tool Quantum ESPRESSO and VASP as well as the device simulator OMEN.

The Big Picture

Integrated electronics constitute one of the most important and spread aspects of our everyday life and among the years the size shrinking of transistors, the active component of all integrated circuits, has been supported and encouraged by several aspects. Obviously, in order to improve the performances of devices, the indefinitely reduction of dimensions can not be the only prospective, but it must be combined with the research of new channel materials able to replace Silicon. Here, the quantum confinement plays a fundamental role, since it has been demonstrated that it significantly affects the properties of nano-sized materials with respect to their bulk counterparts. The simulations will focus on Transition Metal Dichalcogenide(TMDs), which consist of one layer of a transition metal sandwiched between two chalcogen layers. Single-layers of TMD have received a wide attention following the the demonstration of a properly working MoS2 transistor. The final goal would be to found trends able to make the research more target-oriented and less hazarous.

Status: Available

Looking for 1 Semester/Master studen
Contact: Mathieu Luisier

Prerequisites

We are seeking a candidate with a basic knowledge in solid state physics and quantum mechanics. Familiarity withprogramming language (python, c++) as well as ab-initio modeling are appreciated, but not necessary.

Character

40% Theory
40% Simulations
20% Analysis

Professor

Mathieu Luisier

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