Nanoelectronic Modeling Lecture 18: Introduction to RTDs - Quantum Charge Self-Consistency (Hartree)
27 Jan 2010 | Online Presentations | Contributor(s): Gerhard Klimeck
In this semi-classical charge and potential model the quantum mechanical simulation is performed once and the quantum mechanical charge is in general not identical to the semi-classical charge.
Nanoelectronic Modeling Lecture 17: Introduction to RTDs - Relaxation Scattering in the Emitter
Realistic RTDs will have nonlinear electrostatic potential in their emitter. Typically a triangular well is formed in the emitter due to the applied bias and the emitter thus contains discrete quasi bound states.
Nanoelectronic Modeling Lecture 16: Introduction to RTDs - Realistic Doping Profiles
Realistic RTDs need extremely high doping to provide enough carriers for high current densities. However, Impurity scattering can destroy the RTD performance. The dopants are therefore typically spaced 20-100nm away from the central double barrier structure.
Nanoelectronic Modeling Lecture 14: Open 1D Systems - Formation of Bandstructure
27 Jan 2010 | Online Presentations | Contributor(s): Gerhard Klimeck, Dragica Vasileska
The infinite periodic structure Kroenig Penney model is often used to introduce students to the concept of bandstructure formation. It is analytically solvable for linear potentials and shows critical elements of bandstructure formation such as core bands and different effective masses in...
Nanoelectronic Modeling Lecture 12: Open 1D Systems - Transmission through Double Barrier Structures - Resonant Tunneling
This presentation shows that double barrier structures can show unity transmission for energies BELOW the barrier height, resulting in resonant tunneling. The resonance can be associated with a quasi bound state, and the bound state can be related to a simple particle in a box calculation.
Nanoelectronic Modeling Lecture 11: Open 1D Systems - The Transfer Matrix Method
31 Dec 2009 | Online Presentations | Contributor(s): Gerhard Klimeck, Dragica Vasileska, Samarth Agarwal, Parijat Sengupta
The transfer matrix approach is analytically exact, and “arbitrary” heterostructures can apparently be handled through the discretization of potential changes. The approach appears to be quite appealing. However, the approach is inherently unstable for realistically extended devices which exhibit...
Nanoelectronic Modeling Lecture 10: Open 1D Systems - Transmission through & over 1 Barrier
31 Dec 2009 | Online Presentations | Contributor(s): Gerhard Klimeck, Dragica Vasileska, Samarth Agarwal
Tunneling and interference are critical in the understanding of quantum mechanical systems. The 1D time independent Schrödinger equation can be easily solved analytically in a scattering matrix approach for a system of a single potential barrier. The solution is obtained by matching wavefunction...
Nanoelectronic Modeling Lecture 09: Open 1D Systems - Reflection at and Transmission over 1 Step
25 Jan 2010 | Online Presentations | Contributor(s): Gerhard Klimeck, Dragica Vasileska, Samarth Agarwal
One of the most elemental quantum mechanical transport problems is the solution of the time independent Schrödinger equation in a one-dimensional system where one of the two half spaces has a higher potential energy than the other. The analytical solution is readily obtained using a scattering...
Nanoelectronic Modeling Lecture 08: Introduction to Bandstructure Engineering II
25 Jan 2010 | Online Presentations | Contributor(s): Gerhard Klimeck
This presentation provides a brief overview of the concepts of bandstructure engineering and its potential applications to light detectors, light emitters, and electron transport devices. Critical questions of the origin of bandstructure and its dependence on local atom arrangements are raised to...
Nanoelectronic Modeling Lecture 07: Introduction to Bandstructure Engineering I
This presentation serves as a reminder about basic quantum mechanical principles without any real math. The presentation reviews critical properties of classical systems that can be described as particles, propagating waves, standing waves, and chromatography.
Nanoelectronic Modeling Lecture 06: nanoHUB.org - Rappture Toolkit
25 Jan 2010 | Online Presentations | Contributor(s): Gerhard Klimeck, Michael McLennan
The rapid deployment of over 150 simulation tools in just over 4 years has been enabled by 2 critical software developments: 1) Maxwell’s Daemon: a middleware that can deploy at a production level UNIX based codes in web browsers, and 2) Rappture: a software system that enables the rapid...
Nanoelectronic Modeling Lecture 05: nanoHUB.org - Impact on Research
Impact on research is often measured by the number of publications in the scientific literature. The nanoHUB support team has identified 430 citations to nanoHUB.org and/or nanoHUB tools and seminars in the time frame leading up to May 2008 the 430 citations in the scientific literature. 52% of...
Nanoelectronic Modeling Lecture 04: nanoHUB.org - Impact on Education
This presentation will provide a few highlights of how nanoHUB.org is being used in education and what kind of impact it has had so far. Tools and seminars are indeed being used as instructional materials. nanoHUB has been used in over 290 classes in the past few years in over 90 institutions for...
Nanoelectronic Modeling Lecture 03: nanoHUB.org - Online Simulation and More
This presentation provides a brief overview of the nanoHUB capabilites, compares it to static web page delivery, highlights its technology basis, and provides a vision for future cyberinfrastructures in a system of federated HUBs powered by the HUBzero.org infrastructure.
Nanoelectronic Modeling Lecture 02: (NEMO) Motivation and Background
25 Jan 2010 | Online Presentations | Contributor(s): Gerhard Klimeck, Dragica Vasileska
Fundamental device modeling on the nanometer scale must include effect of open systems, high bias, and an atomistic basis. The non-equilibrium Green Function Formalism (NEGF) can include all these components in a fundamentally sound approach and has been the basis for a few novel device...
Nanoelectronic Modeling Lecture 01: Overview
The goal of this series of lectures is to explain the critical concepts in the understanding of the state-of-the-art modeling of nanoelectronic devices such as resonant tunneling diodes, quantum wells, quantum dots, nanowires, and ultra-scaled transistors. Three fundamental concepts critical to...
Nanoelectronic Modeling: From Quantum Mechanics and Atoms to Realistic Devices
25 Jan 2010 | Courses | Contributor(s): Gerhard Klimeck
Your Career Choices after Graduate School and The Most-Neglected Item in your Career Development (2015)
23 Oct 2009 | Online Presentations | Contributor(s): Gerhard Klimeck
What are your career choices after graduate school? Will you develop technology yourself? Will you work in a team? Will you guide people? Where will you work: in industry, research lab, or academia? Regardless where you work, there is generally one item that you are not being taught in graduate...
Advanced Portable Batch System (PBS)
02 Oct 2009 | Presentation Materials | Contributor(s): Xufeng Wang, Kaspar Haume, Gerhard Klimeck
This presentation is a following installment of "Basic Portable Batch System (PBS)" on nanohub.org. Here we discuss some advanced features of PBS and how to adapt them on Purdue's NCN owned clusters.
Basic Portable Batch System (PBS)
This presentation discusses the basics of Portable Batch System (PBS) and how to use it on Purdue's NCN system.
Tutorial for PADRE Based Simulation Tools
10 Aug 2009 | Teaching Materials | Contributor(s): Dragica Vasileska, Gerhard Klimeck
This tutorial is intended for first time and medium level users of PADRE-based simulation modules installed on the nanohub. It gives clear overview on the capabilities of each tool with emphasis to most important effects occuring in nano-scale devices.
Comparison of PCPBT Lab and Periodic Potential Lab
10 Aug 2009 | Presentation Materials | Contributor(s): Abhijeet Paul, Samarth Agarwal, Gerhard Klimeck, Junzhe Geng
This small presentation provides information about the comparison performed for quantum wells made of GaAs and InAs in two different tools. This has been done to benchmark the results from completely two different sets of tools and validate the obtained results. In this presentation we provide...
Exercise for MESFET: Simulation Exercise
03 Aug 2009 | Teaching Materials | Contributor(s): Dragica Vasileska, Gerhard Klimeck
This simulation exercise is designed to illustrate the operation of a MESFET device for different doping of the active region.
Exercise for MESFET: Theoretical Exercises
These theoretical exercises should help the student in understanding the operation of a MESFET device.
Exercise for MOSFET Lab: DIBL Effect
In this exercise students are required to examine the drain induced barrier lowering (DIBL) effect in short channel MOSFET devices.