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Quantum dots have a small, countable number of electrons confined in a small space. Their electrons are confined by having a tiny bit of conducting material surrounded on all sides by an insulating material. If the insulator is strong enough, and the conducting volume is small enough, then the confinement will force the electrons to have discrete (quantized) energy levels. These energy levels can influence the device behavior at a macroscopic scale, showing up, for example, as peaks in the conductance. Because of the quantized energy levels, quantum dots have been called "artificial atoms." Neighboring, weakly-coupled quantum dots have been called "artificial molecules."
Learn more about quantum dots from the many resources on this site, listed below. More information on Quantum dots can be found here.
Self-Assembled Quantum Dot Structure (pyramid)
02 Feb 2011 | | Contributor(s):: Gerhard Klimeck, Insoo Woo, Muhammad Usman, David S. Ebert
Pyramidal InAs Quantum dot. The quantum dot is 27 atomic monolayers wide at the base and 15 atomic monolayers tall.
Quantum Dot Wave Function (still image)
31 Jan 2011 | | Contributor(s):: Gerhard Klimeck, David S. Ebert, Wei Qiao
Electron density of an artificial atom. The image shown displays the excited electron state in an Indium Arsenide (InAs) / Gallium Arsenide (GaAs) self-assembled quantum dot.
Self-Assembled Quantum Dot Wave Structure
31 Jan 2011 | | Contributor(s):: Gerhard Klimeck, Insoo Woo, Muhammad Usman, David S. Ebert
A 20nm wide and 5nm high dome shaped InAs quantum dot grown on GaAs and embedded in InAlAs is visualized.
Modeling the quantum dot growth in the continuum approximation
12 Jan 2011 | | Contributor(s):: Peter Cendula
Quantum dots can grow spontaneously during molecular beam epitaxy oftwo materials with different lattice parameters, Stranski-Krastanow growth mode.We study a mathematical model based on the continuum approximation of thegrowing layer in two dimensions. Nonlinear evolution equation is solved...
Atomistic Modeling and Simulation Tools for Nanoelectronics and their Deployment on nanoHUB.org
16 Dec 2010 | | Contributor(s):: Gerhard Klimeck
At the nanometer scale the concepts of device and material meet and a new device is a new material and vice versa. While atomistic device representations are novel to device physicists, the semiconductor materials modeling community usually treats infinitely periodic structures. Two electronic...
Test for Quantum Dot Lab tool
09 Nov 2010 | | Contributor(s):: SungGeun Kim, Saumitra Raj Mehrotra
This test is aimed at self-learning students or instructors who may be engaged in teaching classes related to the quantum dot lab tool.The level of this test should not be difficult for a student who has gone through "the general tutorial to quantum dots,""the introductory tutorial to the...
Nanoelectronic Modeling Lecture 34: Alloy Disorder in Quantum Dots
05 Aug 2010 | | Contributor(s):: Gerhard Klimeck, Timothy Boykin, Chris Bowen
This presentation discusses the consequences of Alloy Disorder in strained InGaAs Quantum Dots Reminder of the origin of bandstructure and bandstructure engineeringWhat happens when there is disorder?Concept of disorder in the local bandstructureConfiguration noise, concentration noise,...
Nanoelectronic Modeling Lecture 32: Strain Layer Design through Quantum Dot TCAD
04 Aug 2010 | | Contributor(s):: Gerhard Klimeck, Muhammad Usman
This presentation demonstrates the utilization of NEMO3D to understand complex experimental data of embedded InAs quantum dots that are selectively overgrown with a strain reducing InGaAs layer. Different alloy concentrations of the strain layer tune the optical emission and absorption...
Nanoelectronic Modeling Lecture 31a: Long-Range Strain in InGaAs Quantum Dots
04 Aug 2010 | | Contributor(s):: Gerhard Klimeck
This presentation demonstrates the importance of long-range strain in quantum dotsNumerical analysis of the importance of the buffer around the central quantum dot - local band edges – vertical and horizontal extension of the bufferControlled overgrowth can tune the electron energies in the...
Nanoelectronic Modeling Lecture 29: Introduction to the NEMO3D Tool
This presentation provides a very high level software overview of NEMO3D. The items discussed are:Modeling Agenda and MotivationTight-Binding Motivation and basic formula expressionsTight binding representation of strainSoftware structureNEMO3D algorithm flow NEMO3D parallelization scheme –...
Nanoelectronic Modeling Lecture 28: Introduction to Quantum Dots and Modeling Needs/Requirements
20 Jul 2010 | | Contributor(s):: Gerhard Klimeck
This presentation provides a very high level software overview of NEMO1D.Learning Objectives:This lecture provides a very high level overview of quantum dots. The main issues and questions that are addressed are:Length scale of quantum dotsDefinition of a quantum dotQuantum dot examples and...
Nanotechnology Animation Gallery
22 Apr 2010 | | Contributor(s):: Saumitra Raj Mehrotra, Gerhard Klimeck
Animations and visualization are generated with various nanoHUB.org tools to enable insight into nanotechnology and nanoscience. Click on image for detailed description and larger image download. Additional animations are also available Featured nanoHUB tools: Band Structure Lab. Carrier...
12 Apr 2010 | | Contributor(s):: Saumitra Raj Mehrotra, Gerhard Klimeck
In quantum mechanics the time-independent Schrodinger's equation can be solved for eigenfunctions (also called eigenstates or wave-functions) and corresponding eigenenergies (or energy levels) for a stationary physical system. The wavefunction itself can take on negative and positive values and...
Illinois ABE 446 Lecture 3: Quantum Dots and Polymers
11 Feb 2010 | | Contributor(s):: Kaustubh Bhalerao
Nanoelectronic Modeling: Exercises 1-3 - Barrier Structures, RTDs, and Quantum Dots
27 Jan 2010 | | Contributor(s):: Gerhard Klimeck
Exercises:Barrier StructuresUses: Piece-Wise Constant Potential Barrier ToolResonant Tunneling DiodesUses: Resonant Tunneling Diode Simulation with NEGF • Hartree calculation • Thomas Fermi potentialQuantum DotsUses: Quantum Dot Lab • pyramidal dot
Nanoelectronic Modeling: From Quantum Mechanics and Atoms to Realistic Devices
25 Jan 2010 | | Contributor(s):: Gerhard Klimeck
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...
Quantum Dot Lab Demonstration: Pyramidal Qdots
11 Jun 2009 | | Contributor(s):: Gerhard Klimeck, Benjamin P Haley
This video shows the simulation and analysis of a pyramid-shaped quantum dot using Quantum Dot Lab. Several powerful analytic features of this tool are demonstrated.
Thermoelectric Power Factor Calculator for Nanocrystalline Composites
18 Oct 2008 | | Contributor(s):: Terence Musho, Greg Walker
Quantum Simulation of the Seebeck Coefficient and Electrical Conductivity in a 2D Nanocrystalline Composite Structure using Non-Equilibrium Green's Functions
Nanobiotechnology – a different perspective
out of 5 stars
22 Jul 2008 | | Contributor(s):: Murali Sastry
The study of the synthesis, exotic properties, assembly/packaging and potential commercial application of nanomaterials is an extremely important topic of research that is expected to have far-reaching global impact. The focus of my talk will be on an emerging branch of nanotechnology that...
Nano Carbon: From ballistic transistors to atomic drumheads
14 May 2008 | | Contributor(s):: Paul L. McEuen
Carbon takes many forms, from precious diamonds to lowly graphite. Surprisingly, it is the latter that is the most prized by nano physicists. Graphene, a single layer of graphite, can serve as an impenetrable membrane a single atom thick. Rolled up into a nanometer-diameter cylinder--a carbon...