
Thermoelectric Nanotechnology
27 Jul 2010   Contributor(s):: Mark Lundstrom
his talk is an undergraduate level introduction to the field. After a brief discussion of applications, the physics of the Peltier effect is described, and the Figure of Merit (FOM), ZT, which controls the efficiency of a thermoelectric refrigerator or electric power generator, is discussed. The...

ABACUS Exercise: Bandstructure – KronigPenney Model and TightBinding Exercise
20 Jul 2010   Contributor(s):: Dragica Vasileska, Gerhard Klimeck
The objective of this exercise is to start with the simple KronigPenney model and understand formations of bands and gaps in the dispersion relation that describes the motion of carriers in 1D periodic potentials. The second exercise examines the behavior of the bands at the Brillouin zone...

Nanoelectronic Modeling Lecture 25a: NEMO1D  Full Bandstructure Effects
07 Jul 2010   Contributor(s):: Gerhard Klimeck
(quantitative RTD modeling at room temperature)

Band Structure Lab Exercise
28 Jun 2010   Contributor(s):: Gerhard Klimeck, Parijat Sengupta, Dragica Vasileska
Investigations of the electron energy spectra of solids form one of the most active fields of research. Knowledge of band theory is essential for application to specific problems such as Gunn diodes, tunnel diodes, photodetectors etc. There are several standard methods to compute the band...

Ripples and Warping of Graphene: A Theoretical Study
08 Jun 2010   Contributor(s):: Umesh V. Waghmare
We use firstprinciples density functional theory based analysis to understand formation of ripples in graphene and related 2D materials. For an infinite graphene, we show that ripples are linked with a low energy branch of phonons that exhibits quadratic dispersion at long wavelengths. Many...

TightBinding Band Structure Calculation Method
08 Jun 2010   Contributor(s):: Dragica Vasileska, Gerhard Klimeck
This set of slides describes on simple example of a 1D lattice, the basic idea behind the TightBinding Method for band structure calculation.

InAs: Evolution of isoenergy surfaces for heavy, light, and splitoff holes due to uniaxial strain.
25 May 2010   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: [001], [110], [111]Carrier type: LH, HH, SOHStrain...

Band Structure Calculation: General Considerations
17 May 2010   Contributor(s):: Dragica Vasileska
This set of slides explains to the users the concept of valence vs. core electrons, the implications of the adiabatic approximation on the separation of the total Hamiltonian of the system and the meanfield approximation used in ab initio bandstructure approaches. It then gives systematic...

Empirical Pseudopotential Method: Theory and Implementation
17 May 2010   Contributor(s):: Dragica Vasileska
This tutorial first teaches the users the basic theory behind the Empirical Pseudopotential (EPM)Bandstructure Calculation method. Next, the implementation details of the method are described and finally a MATLAB implementation of the EPM is provided.vasileska.faculty.asu.eduNSF

ninithi
13 May 2010   Contributor(s):: Chanaka Suranjith Rupasinghe, Mufthas Rasikim
ninithi which is a free and opensource modelling software, can be used to visualize and analyze carbon allotropes used in nanotechnology. You can generate 3D visualization of Carbon nanotubes, Fullerenes, Graphene and Carbon nanoribbons and analyze the band structures of nanotubes and graphene.

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...

Electronic band structure
12 Apr 2010   Contributor(s):: Saumitra Raj Mehrotra, Gerhard Klimeck
In solidstate 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...

Nanoelectronic Modeling Lecture 25b: NEMO1D  Hole Bandstructure in Quantum Wells and Hole Transport in RTDs
09 Mar 2010   Contributor(s):: Gerhard Klimeck
Heterostructures such as resonant tunneling diodes, quantum well photodetectors and lasers, and cascade lasers break the symmetry of the crystalline lattice. Such break in lattice symmetry causes a strong interaction of heavy, light and splitoff hole bands. The bandstructure of holes and the...

Nanoelectronic Modeling Lecture 26: NEMO1D 
09 Mar 2010   Contributor(s):: Gerhard Klimeck
NEMO1D demonstrated the first industrial strength implementation of NEGF into a simulator that quantitatively simulated resonant tunneling diodes. The development of efficient algorithms that simulate scattering from polar optical phonons, acoustic phonons, alloy disorder, and interface roughness...

Bulk Bandstructure in MATLAB: Pseudopotential Method
08 Feb 2010   Contributor(s):: Muhanad Zaki
This code (MATLAB) readily calculates and plots the bandstructure of Silicon (bulk) using the empirical pseudopotential method.Detailed instructions are in the compressed archive.I hope it would be a useful/interesting educational toolNote: If you are running this code in a nonWindows OS (e.g....

nanoMATERIALS SeqQuest DFT
04 Feb 2008   Contributor(s):: Ravi Pramod Kumar Vedula, Greg Bechtol, Benjamin P Haley, Alejandro Strachan
DFT calculations of materials

Illinois ECE 440: Diffusion and Energy Band Diagram Homework
27 Jan 2010   Contributor(s):: Mohamed Mohamed
This homework covers Diffusion of Carriers, Builtin Fields and Metal semiconductor junctions.

Nanoelectronic Modeling: Exercises 13  Barrier Structures, RTDs, and Quantum Dots
27 Jan 2010   Contributor(s):: Gerhard Klimeck
Exercises:Barrier StructuresUses: PieceWise 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 Lecture 14: Open 1D Systems  Formation of Bandstructure
25 Jan 2010   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
25 Jan 2010   Contributor(s):: Gerhard Klimeck, Dragica Vasileska
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.