tiberCAD is a software tool for numerical simulation in the field of electronic and optoelectronic devices. It allows to model and design innovative and nanostructured devices, such as III/V LEDs, nanowire FETs, Dye Solar Cells (DSCs). Both Atomistic and Continuous FEM-based models are available.

General Features

• Several continuous level physical models based on Finite Elements (FEM)
• Atomistic models for energy relaxation and quantum calculations in crystalline structures: VFF, Empirical Tight-Binding
  
• Built-in Atomistic Generator to generate an atomic structure based on the material specifications associated with the finite element mesh
• Extensive material database: zincblend and wurtzite material compounds, ternary and quaternary alloys
• 1D/2D/3D modeling and meshing, cylindrical symmetry
• Support for output data visualization (vtk format)
• MPI parallelization: MPI communicators can be assigned to devices and modules
  (Linux version)
  

Multiscale/Multiphysics

tiberCAD is a multiphysics tool, that is it is able to solve different physical models involved in device simulation. It is also a multiscale tool, since it allows the simultaneous solution of physical models on different length scales, ranging from FEM continuous models to atomistic descriptions.

With tiberCAD, quantum and classical descriptions can be used in different regions of a device/nanostructure within the same simulation; analysis and optimization may be performed at all the relevant length scales, possibly including self-consistent coupling of different models, such as quantum/drift-diffusion and thermal/drift-diffusion.

A Valence Force Field (VFF) model for the relaxation of crystalline structures allows to take into account internal strain. VFF may be used in combination with other atomistic methods, such as Empirical Tight Binding (ETB), for the calculation of electronic and optical properties of Nanowires, Quantum Dots and Quantum Wells. Such atomistic simulation models may be coupled to continuous level models for transport and light generation.

Physical models

• Strain/stress modelization, including pyro- and piezoelectric effects, non-linear strain, converse piezoelectric, external forces
• Classical Drift-Diffusion particle transport coupled to Poisson calculation
• Models for transport in organic devices (OLEDs), including Gaussian Density of States (DOS) and Hopping mobility model
• Electrons, holes and excitons dynamic
• Heat balance model
• Quantum physics for continuous media, based on multi-bands EFA (Envelope Function Approximation) k·p theory
• Valence Force Field (VFF) module for atomistic-based structure relaxation
• Atomistic-based Empirical Tight Binding (ETB) calculations of electronic and optical properties, including random alloy approach to treat in a fundamental way alloy fluctuations in LED active regions.
• Accurate ETB sp³s^*d parameterization for several materials, including GaN/AlGaN/InGaN systems.

With tiberCAD it is possible to perform reliable simulations by taking into account the most important physical concepts emerging in the last developments of nanoelectronics and nanotechnology, such as quantum mechanical effects, strain and polarization in heterostructure semiconductor devices, self-heating and thermal transport.

Here are some of the device applications of tiberCAD

• Electronic devices analysis and design (HEMT, MOSFET, BJT,etc)
• Nanoelectronic devices (nanoMOSFET, nanowire FETs etc.)
• Optoelectronic Devices (LEDs, OLEDs, Photodetectors)
• Solar Cells (silicon based solar cells, DSSC, tandem cells)
• Nanostructures (quantum wells, quantum dot, Nanowires, III/V heterostructures)

For more information, applications and documentation on tiberCAD project see also www.tibercad.org.

tiberCAD package includes several modules, each created to solve a particular problem in device physics:

• Elasticity: to study mechanical deformation and lattice-mismatch strain in heterostructures

• Thermal: to perform thermal analysis and heat flow calculations

• Drift-Diffusion: to calculate charge transport for holes, electrons, excitons

• EFA: to find quantum states in confined nanostructures (quantum dots and wells, nanowires), with a multi-band quantum model

• DSC: a special module for the simulation of innovative Dye-Sensitized Solar Cells

• ATOMISTIC: suite of tools for atomistic calculations, incuding Modules for Valence Force Field and Empirical Tight Binding