Quantum dots on a semiconductor surface

Stylized depiction of quantum dots on a semiconductor surface based on an atomic-force microscope image.

Project Notes

This image was created from actual atomic-force microscope data, which was used as a displacement texture to create the 3D landscape seen above.

A quantum dot is a tiny semiconductor particle, as small as 10 nanometers (nm) in diameter. These little crystals are so small that they have discrete electronic states, just like an atom — they are sometimes called “artificial atoms” for this reason. And just like an atom, the electrons in a quantum dot can be “excited” to higher energy states by absorbing light of precisely the right color. Eventually, the electrons “relax” back to their original energy state, emitting a photon in the process — in the image above, three quantum dots are emitting photons after being excited.

The ability to emit precise monochromatic light makes quantum dots immensely useful, from enhancing the colors in LCD screens to enabling high-resolution medical imaging of tumor structure.