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Quantum Dot Wave Function (Quantum Dot Lab)
02 Feb 2011 | Animations | Contributor(s): Gerhard Klimeck, David S. Ebert, Wei Qiao
Electron density of an artificial atom. The animation sequence shows various electronic states in an Indium Arsenide (InAs)/Gallium Arsenide (GaAs) self-assembled quantum dot.
Self-Assembled Quantum Dot Structure (pyramid)
02 Feb 2011 | Animations | 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 | Animations | 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 | Animations | 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.
Electron Density in a Nanowire
30 Jan 2011 | Animations | Contributor(s): Gerhard Klimeck, Saumitra Raj Mehrotra
Electron Density in a circular Silicon nanowire transistor.
Tunneling in an Nanometer-Scaled Transistor
25 Jan 2011 | Animations | Contributor(s): Gerhard Klimeck, Mathieu Luisier, Neerav Kharche, George A. Howlett, Insoo Woo, David Ebert
Electrons tunneling through the gate of an ultra-scaled transistor.
InAs: Evolution of iso-energy surfaces for heavy, light, and split-off holes due to uniaxial strain.
25 May 2010 | Animations | Contributor(s): Abhijeet Paul, Denis Areshkin, Gerhard Klimeck
Movie was generated using Band Structure Lab tool at nanoHUB and allows to scan over four parameters:Hole energy measured from the top of the corresponding band (i.e. the origin of energy scales for LH and SOH is different)Strain direction: , , Carrier type: LH, HH, SOHStrain...
Fermi-Dirac statistics with temperature
15 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck
Fermi-Dirac statistics is applied to identical particles with half-integer spin (such as electrons) in a system that is in thermal equilibrium. Since particles are assumed to have negligible mutual interactions, this allows a multi-particle system to be described in terms of single-particle...
Diffusion of holes and electrons
Diffusion is a process of particles distributing themselves from regions of high- to low- concentrations. In semi-classical electronics these particles are the charge carriers (electrons and holes). The rate at which a carrier can diffuse is called diffusion constant with units of cm2/s. The...
CV profile with different oxide thickness
20 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck
C-V (or capacitance-voltage) profiling refers to a technique used for the characterization of semiconductor materials and devices. C-V testing is often used during the characterization process to determine semiconductor parameters, particularly in MOSCAP and MOSFET structures.C-V measurements...
Electronic band structure
12 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck
In solid-state physics, the electronic band structure (or simply band structure) of a solid describes ranges of energy in which an electron is "forbidden" or "allowed". The band structure is also often called the dispersion or the E(k) relationship. It is a mathematical relationship between the...
Graphene nanoribbon bandstructure
17 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck
Graphene nanoribbons (often abbreviated as GNR) are planar strips of graphene with a thickness of approximately one atom. Carbon atoms in graphene are sp2-hybridized with a carbon-carbon bond length of approximately 0.142 nm. As an electronic material, graphene exhibits many desirable...
Carbon nanotube bandstructure
22 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck
Carbon nanotubes are allotropes of carbon with a cylindrical nanostructure, and can be categorized into single-walled nanotubes (SWNT) and multi-walled nanotubes (MWNT). These cylindrical carbon molecules have novel properties that make them potentially useful in many nanotechnology...
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...
Threshold voltage in a nanowire MOSFET
22 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, SungGeun Kim, Gerhard Klimeck
Threshold voltage in a metal oxide semiconductor field-effect transistor (better known as a MOSFET) is usually defined as the gate voltage at which an inversion layer forms at the interface between the insulating layer (oxide) and the substrate (body) of the transistor. A MOSFET is said to be...
Local density of states
The concept of general density of states (DOS) in devices is, by definition, spatially invariant. However, in the case of inhomogeneous materials or in quantum confined structures, the density of states can be resolved in space. This is known as local density of states, or LDOS. …
Resonant Tunneling Diode operation
A resonant tunneling diode (RTD) is a type of diode with a resonant tunneling structure that allows electrons to tunnel through various resonant states at certain energy levels. RTDs can be fabricated using many different types of materials (such as III-V, type IV, II-VI semiconductors) and...
PN junction in forward bias
A PN junction is formed by joining p-type and n-type doped semiconductors together in very close contact. The p- and n-type semiconductors are conducting because of the available free carriers. However, because the carriers diffuse into the adjoining p and n regions by a process called...
Graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. Graphene sheets are weakly bonded to other graphene layers above and below to form Graphite. The difference between two layers is approximately 0.335 nm .Graphite can...
16 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck
A fullerene is any molecule composed entirely of carbon, and can take the form of hollow spheres, ellipsoids, or tubes. Spherical fullerenes (often referred to as "buckyballs") are one of the known structurally different form of carbon. C60 are the most common of buckyball structures. …
Quantum Dot Lab Demonstration: Pyramidal Qdots
11 Jun 2009 | Animations | 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.
PN Junction Lab Demonstration: Asymmetric PN Junctions
This video shows the simulation and analysis of a several PN junctions using PN Junction Lab, which is powered by PADRE. Several powerful analytic features of this tool are demonstrated.
Periodic Potential Lab Demonstration: Standard Kroenig-Penney Model
This video shows the simulation of a 1D square well using the Periodic Potential Lab. The calculated output includes plots of the allowed energybands, a table of the band edges and band gaps, plots of reduced and expanded dispersion relations, and plots comparing the dispersion relations to...
Piece-Wise Constant Potential Barriers Tool Demonstration: Bandstructure Formation with Finite Superlattices
This video shows the simulation and analysis of a systems with a series of potential barriers. Several powerful analytic features of Piece-wise Constant Potential Barrier Tool (PCPBT) are demonstrated.
OMEN Nanowire Demonstration: Nanowire Simulation and Analysis
This video shows the simulation and analysis of a nanowire using OMEN Nanowire. Several powerful analytic features of this tool are demonstrated.