Electron Density in a Nanowire

30 Jan 2011 | Animations | Contributor(s): Gerhard Klimeck, Saumitra Raj Mehrotra

Electron Density in a circular Silicon nanowire transistor.

Crystal Viewer Tool Video Demonstration

14 Dec 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Lynn Zentner, Joseph M. Cychosz

This video shows the use of the Crystal Viewer Tool to visualize several material/crystal systems. The examples demonstrated will provide a first-time user with a basic understanding of how the tool works.

Carrier Statistics Lab Video Demonstration

23 Sep 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra

This video shows: Basic input deck for the tool, Simulation run of Temperature sweep with constant fermi level, Simulation run of Temperature sweep with constant doping.

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 applications, …

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 …

Resonant Tunneling Diode operation

22 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck

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 …

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 …

PN junction in forward bias

17 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck

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 …

Local density of states

17 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck

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. …

Graphite

17 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck

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 [1]. Graphite can …

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 properties, …

Buckyball C60

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. …

Diffusion of holes and electrons

15 Apr 2010 | Animations | Contributor(s): Saumitra Raj Mehrotra, Gerhard Klimeck

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 image …

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 energy …

3D wavefunctions

12 Apr 2010 | Animations | 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 …

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 …