Carrier Statistics Tool Verification

10 Aug 2010 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Dragica Vasileska, Gerhard Klimeck

This test verifies the Carrier Statistics Tool by comparing the numerically computed and analytically extracted, electron and hole carrier densities. The results are close within 2% of margin.

ABACUS: Test for Carrier Statistics Tool

10 Aug 2010 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Dragica Vasileska, Gerhard Klimeck

The objective of this test is to give an idea to a self-learning students or to instructors in the case this test is used in a classroom the level of understanding of this topic when students have gone through the learning material, worked exercises and have completed the assignments and the …

Carrier Statistics - Temperature Effects

10 Aug 2010 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Dragica Vasileska, Gerhard Klimeck

Silicon (Si), Germanium (Ge) and Gallium-Arsenide (GaAs) are commonly used materials for MOS Field Effect Transistor (MOSFET) fabrication. MOSFET structures are commonly doped to achieve the desired switching operation and doping is a critical parameter in MOSFET designing. The goal in this test is …

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 …

Nanotechnology Animation Gallery

22 Apr 2010 | Teaching Materials | 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 …

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 …

BJT Lab: First-Time User Guide

15 Jun 2009 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Benjamin P Haley

This first-time user guide provides introductory material to BJT on nanoHUB. It includes a tour of the Rappture interface, which notes key inputs and typical outputs, and an introduction to the workings of NPN and PNP type BJT. We discuss the default simulation (what happens if you don't change …

Drift Diffusion Lab: First-Time User Guide

13 Jun 2009 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Benjamin P Haley

This first-time user guide provides introductory material to Drift Diffusion Lab on nanoHUB. It includes a tour of the Rappture interface, which notes key inputs and typical outputs. It also provides an introduction to concepts of drift and diffusion in a semiconductor. We discuss the default …

MOSFet: First-Time User Guide

13 Jun 2009 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Benjamin P Haley

This first-time user guide provides introductory material to MOSFet on nanoHUB. The introduction to MOSFETs and SOI-MOSFETs is followed by a tour of the Rappture interface, which notes key inputs and typical outputs. We discuss the default simulation (what happens if you don't change any inputs, …

PN Junction Lab: First-Time User Guide

13 Jun 2009 | Teaching Materials | Contributor(s): Saumitra Raj Mehrotra, Benjamin P Haley

This first-time user guide provides introductory material to PN Junction Lab on nanoHUB. The introduction to PN junctions is followed by a tour of the Rappture interface, which notes key inputs and typical outputs. We discuss the default simulation (what happens if you don't change any inputs, and …

Carrier Statistics Lab: First-Time User Guide

09 Mar 2009 | Teaching Materials | Contributor(s): Abhijeet Paul, Gerhard Klimeck, Benjamin P Haley, Saumitra Raj Mehrotra

This first-time user guide is an introduction to the Carrier Statistics Lab . It provides basic definitions, guidance on how to run the tool, and suggested exercises to help users get accustomed to the idea of distribution functions as well as how these functions are used in determining the …

OMEN Nanowire: First-Time User Guide

23 Feb 2009 | Teaching Materials | Contributor(s): SungGeun Kim, Benjamin P Haley, Mathieu Luisier, Saumitra Raj Mehrotra, Gerhard Klimeck

This is the first-time user guide for OMEN Nanowire. In addition to showing how the tool operates, it briefly explains what the OMEN Nanowire is, what it can do, and the input and output relationship. NCN@Purdue [1] Sung Dae Suk, et. al., IEDM, 2005, "High Performance 5nm radius Twin Silicon …

OMEN Nanowire

02 Sep 2008 | Tools | Contributor(s): SungGeun Kim, Mathieu Luisier, Benjamin P Haley, Abhijeet Paul, Saumitra Raj Mehrotra, Gerhard Klimeck

Full-band 3D quantum transport simulation in nanowire structure

MESFET Lab

26 Jul 2008 | Tools | Contributor(s): Dragica Vasileska, Gerhard Klimeck, Saumitra Raj Mehrotra

This tool gives insight into the basic operation of MESFET devices