Conical Quantum Dot

Application ID: 723

Quantum dots are nano- or microscale devices created by confining free electrons in a 3D semiconducting matrix. Those tiny islands or droplets of confined “free electrons” (those with no potential energy) present many interesting electronic properties. They are of potential importance for applications in quantum computing, biological labeling, or lasers, to name only a few.

Quantum dots can have many geometries including cylindrical, conical, or pyramidal. This model studies the electronic states of a conical InAs quantum dot grown on a GaAs substrate. To compute the electronic states taken on by the quantum dot/wetting layer assembly embedded in the GaAs surrounding matrix, the 1-band Schrödinger equation is solved. The four lowest electronic energy levels with corresponding eigenwave functions for those four states are solved in this model using the Coefficient form in COMSOL Multiphysics.

The model was based upon the paper: R. Melnik and M. Willatzen, “Band structure of conical quantum dots with wetting layers,” Nanotechnology, vol. 15, 2004, pp. 1-8.

This model example illustrates applications of this type that would nominally be built using the following products: