It was shown that the electronic wave functions in quantum dots resemble the ones in real atoms.

For these reasons, quantum dots are sometimes referred to as artificial atoms, emphasizing their bound and discrete electronic states, like naturally occurring atoms or molecules. The quantum dot absorption and emission features correspond to transitions between discrete quantum mechanically allowed energy levels in the box that are reminiscent of atomic spectra. The confinement is similar to a three-dimensional particle in a box model. Nanoscale semiconductor materials tightly confine either electrons or electron holes. The color of that light depends on the energy difference between the conductance band and the valence band, or the transition between discrete energy states when the band structure is no longer well-defined in QDs. This light emission ( photoluminescence) is illustrated in the figure on the right. The excited electron can drop back into the valence band releasing its energy as light. In the case of a semiconducting quantum dot, this process corresponds to the transition of an electron from the valence band to the conductance band. When the quantum dots are illuminated by UV light, an electron in the quantum dot can be excited to a state of higher energy. They are a central topic in nanotechnology and materials science. Quantum dots ( QDs) - also called semiconductor nanocrystals, are semiconductor particles a few nanometres in size, having optical and electronic properties that differ from those of larger particles as a result of quantum mechanics.

Quatum dot solarcell