3.4. Tutorials

Many of the nextnano++ tutorials have equivalent input files for nextnano³. However, some features are only available in nextnano³, e.g. tight-binding, electrolytes, graphene and mobility calculations.

Band structure

• Empirical tight-binding sp³s^* band structure of GaAs, GaP, AlAs, InAs, C (diamond) and Si
• Tight-binding band structure of graphene
• 30-band \(\mathbf{k}\cdot\mathbf{p}\) band structure calculation

Semiconductor Physics

• Doping in semiconductors: Incomplete ionization

Heterostructures

• Quantum Confined Stark Effect (QCSE)
• Optical interband absorption in a quantum well including excitonic effects
• Schottky barrier

Transmission

• Efficient method for the calculation of ballistic quantum transport - The CBR method (2D example)
• Transmission through a 3D nanowire (3D example)
• 1D - Quantum Tunneling: Comparison of CBR- and WKB approaches with the exact answer
• 1D - Quantum Tunneling and Fowler-Nordheim theory

Electrolyte

• Poisson–Boltzmann equation: The Gouy–Chapman solution
• — DEV — Charge accumulation at the diamond–electrolyte interface

Unfortunately, many nextnano³ tutorials have not been moved yet to the new documentation.

Here is a list of these old tutorials.

• Tutorials indicated by (++) are also available for nextnano++.

• Tutorials indicated by (Ma) already moved to the new documentation.

Quantum Mechanics

• (++) (Ma) Triangular well

• (++) (Ma) Parabolic quantum well

• (++) (Ma) Double quantum well

• (++) (Ma) Dispersion in infinite superlattices: Minibands (Kronig-Penney model)

• (++) (Ma) Quantum corral (2D)

• (++) (Ma) Quantum wire (2D)

• (++) (Ma) Artificial atom (3D)

• (++) (Ma) Efficient method for the calculation of ballistic quantum transport - The CBR method (2D example)

• (++) (Ma) Transmission function - NEGF

• (++) (Ma) Transmission through a 3D nanowire (3D)

• (++) (Ma) Exciton correction in 1D quantum wells

Semiconductor Physics

• (++) (Ma) p-n junction

• Electron density in doped semiconductors (Si, Ge, GaAs) - Compensated semiconductors

• Density in n-doped GaAs - Comparison of classical, quantum, k.p and full-band density k.p approach

• (++) (Ma) Poisson equation (for different charge density profiles)

Strain and Piezoelectricity

• (++) Strain: Band shifts and splittings due to conduction and valence band deformation potentials

• (++) (Ma) Band gap of strained AlGaInP on GaAs substrate

• (++) Strain and displacement tensors along different growth directions

• Growth of layers on strained (or stressed) substrates (biaxial and uniaxial)

• strained silicon

• (++) Piezoelectric fields due to strain (Quantum well)

• Piezoelectric field in InAs/GaAs QWs grown along the [111] orientation

• (++) GaN/AlN wurtzite structure: Strain, piezo and pyroelectric charges in wurtzite

• (++) (Ma) Strain effects in freestanding three-dimensional nitride nanostructures (3D)

Magnetic field

• (++) (Ma) Landau levels in bulk GaAs (magnetic field) (2D)

• (Ma) Fock-Darwin states of a 2D parabolic potential (magnetic field) (2D)

• (Ma) Fock-Darwin states of a 2D parabolic, anisotropic (elliptical) potential in a magnetic field (2D)

• Vertically coupled quantum wires in a longitudinal magnetic field (2D)

Heterostructures

• Strained AlAs QW - Crossover of ground states

• (++) (Ma) Schrödinger equation of a two-dimensional core-shell structure Hexagonal 2DEG - Two-dimensional electron gas in a delta-doped hexagonal shaped GaAs/AlGaAs nanowire heterostructure (2D)

• (++) (Ma) Electron and hole wave functions in a T-shaped quantum wire grown by CEO (cleaved edge overgrowth) (2D)

• (++) (Ma) Electron and hole wave functions in a strained T-shaped quantum wire grown by CEO (cleaved edge overgrowth) (2D)

• (++) (Ma) Cubic and cuboidal shaped quantum dots (3D)

• Nanocrystals (3D)

• (++) (Ma) Artificial quantum dot crystal - Superlattice dispersion (minibands) (3D)

• Intermediate-band solar cell (artificial quantum dot crystal) (3D)

• (++) (Ma) Energy levels in a pyramidal shaped InAs/GaAs quantum dot including strain and piezoelectric fields (3D)

• Exciton correction in 2D quantum wires (2D)

• Exciton and biexciton correction in idealistic 3D cubic quantum dots (3D)

• (++) (Ma) QD molecule (3D)

• Cleaved edge overgrowth quantum dots (CEO QDs) (3D)

• (++) (Ma) Hexagonal shaped GaN quantum dot embedded in AlN (wurtzite) (3D)

k.p

• (++) (Ma) k.p dispersion in bulk GaAs (strained / unstrained)

• (++) (Ma) k.p dispersion in bulk GaN (strained / unstrained) (wurtzite)

• (++) (Ma) k.p dispersion in bulk unstrained ZnS, CdS, CdSe and ZnO (wurtzite)

• (++) (Ma) k|| energy dispersion of holes in a GaAs/AlAs quantum well - How to modify database parameters in the input file.

• (++) (Ma) k|| energy dispersion of holes in a GaN/AlGaN quantum well

• k|| energy dispersion of holes in unstrained and strained silicon inversion layers

• Electron density of states (DOS) of a GaAs quantum well and Hole density of states (DOS) of a Si hole channel

• Self-consistent 6-band k.p calculations of holes in strained Si/SiGe MOSFETs

• (++) (Ma) Energy dispersion of a cylindrically shaped GaN nanowire (2D)

• (++) (Ma) Artificial atom (Si QD) - 6-band k.p (3D)

• Single-band is a special case of 8-band k.p if the electrons are decoupled from the holes

  • Self-consistent calculation of the quantum mechanical density within the single-band approximation and 8-band k.p

  • Calculation of the quantum mechanical density from the k.p dispersion (no self-consistency)

• 2D Tutorial of the 1D tutorial: Single-band (‘effective-mass’) is a special case of 8-band k.p (‘8x8kp’) if the electrons are decoupled from the holes (2D)

  • Calculating the quantum mechanical density within the single-band approximation and 8-band k.p self-consistently

  • Calculation of the quantum mechanical density from the k.p dispersion (no self-consistency)

T2SL

• (++) (Ma) InAs / In0.4Ga0.6Sb superlattice dispersion with 8-band k.p (type-II band alignment)

• (++) (Ma) InAs / GaSb broken gap quantum well (BGQW) (type-II band alignment)

• HgTe/CdTe quantum well (available on request; \(\mathbf{k} \cdot \mathbf{p}\) and tight-binding)

2DEGs

• Mobility in two-dimensional electron gases (2DEGs)

• (++) (Ma) Schrödinger-Poisson

• (++) (Ma) Si/SiGe MODQW (Modulation Doped Quantum Well)

• (++) (Ma) HEMT structure (High Electron Mobility Transistor)

• inverted High Electron Mobility Transistor (HEMT)

• (++) (Ma) Two-dimensional electron gas in an AlGaN/GaN field effect transistor

• (++) (Ma) Single-electron transistor (3D)

Optoelectronics

• (++) (Ma) Cascade solar cell (AlGaAs/InGaAs Tandem solar cell)

• (++) (Ma) Quantum Cascade Laser (simple structure)

• (++) (Ma) Quantum Cascade Laser

• (++) (Ma) Intraband transitions

• (++) (Ma) Interband transitions

• (++) (Ma) Intersubband transitions in InGaAs/AlInAs multiple quantum well systems

• (++) (Ma) Scattering times for electrons in unbiased and biased single and multiple quantum wells

• Optical absorption of an InGaAs quantum well

Electronics

• (++) (Ma) Capacitance-Voltage (C-V) curve of a “metal”-insulator-semiconductor (MIS) structure

• p-Si / SiO2 / poly-Si structure (MOSFET with inversion channel due to applied gate voltage)

• (++) (Ma) Resistance in bulk n-type doped silicon

• (++) (Ma) n-i-n Si resistor (classical and quantum mechanical current calculation)

• I-V characteristics of an n-doped Si structure

• (++) (Ma) I-V characteristics of an n-i-n-doped Si structure

• (++) (Ma) Ultrathin-body Double Gate FET - Double Gate MOSFET (Metal Oxide Semiconductor Field Effect Transistor) (2D)

• (++) (Ma) Double Gate MOSFET (5 nm) (quantum mechanical calculation) (2D)

• (Ma) Electron wave functions of a 2D slice of a Triple Gate MOSFET (2D)

NEGF

• Ballistic current in a resonant tunneling diode (RTD)

Electrolyte

for e.g. Ion-Sensitive Field Effect Transistors (ISFETs)

• Extended Poisson-Boltzmann equation: Potentials of mean force (PMF)

• Detection of proteins with a SOI (silicon-on-insulator) electrolyte sensor

• Si-SiO2 electrolyte sensor

• Electrolyte Gate AlGaN/GaN Field Effect Transistor as pH Sensor

• Diamond biosensors (available on request)

Graphene

• Carrier statistics of graphene sheets

Hello World

• Simple SiGe structure (This is a very ancient tutorial and was written 20 years ago. Meanwhile the software has evolved.)

  • Step 1: Simple SiGe structure (input_file1.in)

  • Step 2: Include current (input_file2.in)

  • Step 3: Include quantum models (1-band Schrödinger equation) (input_file3.in)

  • Step 4: Read in data and solve k.p (input_file4.in)

  Four example input files are provided in this tutorial which represent typical simulation settings that are connected to each other. These files contain extensive comments to guide you through your first experience with the input system.