logo EFA tiberCAD module Nanostructured devices exploiting quantum mechanical effects for their functioning e.g. transistors based on quantum wires, quantum dots or molecules, are on the cutting edge of nanotechnology. To model the electronic and optical behavior of the active regions of such devices a fully quantum mechanical treatment is required. The Envelope Function Approximation (EFA) allows a rigorous quantum description of semiconductor heterostructures.
Examples of applications are: full 3D calculation of quantum states in a GaN-based nanocolumn quantum disk, optical properties of AlGaN/GaN LED diode, InGaAs/GaAs quantum wires.

The EFA Module allows to perform 1, 2 and 3D quantum calculations in the framework of Envelope Function Approximation (EFA): the Hamiltonian of the system is constructed in the framework of single-band and multiband 6x6 or 8x8 k·p theory, including the local corrections due to strain. Eigenstates and eigenfunctions of the given system, as well as the quantum density of electron and holes and the dispersion of quantum states in the k-space can be calculated. efa screenshot Optical matrix and probabilities of optical transitions can be found and used to obtain the optical spectrum from spontaneous emission, for k=0 or with a full integration in k-space. Nitrides wurzite crystalline structure are fully supported. Self-consistent coupling with Poisson/Drift-Diffusion model is implemented.

Main characteristics of the model:

  • Modeling of 1, 2 and 3D structures: quantum dots, quantum wires, NWFETs, nanowires
  • Single band and multiband 6x6, 8x8 k·p model
  • Zincblende and wurzite crystalline structures fully supported including strain corrections
  • Possible coupling with Drift-Diffusion Module for self-consistent Schrödinger/Poisson simulation