Quantum Dots
Nanometer-scale semiconductor crystals that trap charge carriers in all three spatial dimensions, exhibiting artificial atom quantized energy spectra.
Governing formula
E_gap(R) = E_bulk + (ℏ² π²) / (2 m_eff R²)
SI unit
nm (Size), eV (Bandgap)
In depth
Due to 3D quantum confinement, energy level spacing depends directly on quantum dot radius R. Smaller quantum dots emit higher energy blue light, whereas larger dots emit red light.
Examples in the real world
QLED television displays producing vibrant pure colors, and fluorescent bio-labeling tags in medical imaging.