The confinement energy for a nanostructure depends on the details of the confining potential and the band structure. For a single band with effective mass m*, however, if we approximate the structure as having a constant potential in the “well” and another constant potential in the “barrier”, with a linear dimension “L” for the overall structure, the confinement energy is determined. The graphs below can be used to obtain confinement energies in such a single-band approximation.

This gives the confinement energy in a core-shell wire with a hexagonal cross section.

Here is a text file with the data for the graph above:

This gives the confinement energies for quantum wells, wires with circular cross section, and spherical dots