The distance between the electron in the conduction band and its hole in the valence band is called the Bohr radius. The diameter of a QD is in the same order as its exciton Bohr radius ...

"We attribute this suppression to a reduced exciton Bohr radius and exciton diffusion coefficient, as extracted from optical ...

This confinement is effective when the size of the particle is comparable to or smaller than what is called the “exciton Bohr radius” of the material, which is typically a few nanometers This ...