Phonon Bottleneck: Hot-Carrier Cooling in a Quantum Dot

Quantum confinement turns a semiconductor's continuous conduction band into a discrete ladder of energy levels, and that ladder can trap a photoexcited "hot" electron: single-LO-phonon emission only conserves energy when the level spacing matches the crystal's fixed phonon energy, so a mismatched ladder stalls relaxation for far longer than in bulk material — the phonon bottleneck. This simulator renders the level ladder in 3D and steps a real electron down it with a Fermi-golden-rule-style resonance rate, sets the LO-phonon energy from a real material choice (GaAs, InAs, CdSe), and lets an Auger-assisted channel bypass the bottleneck by dumping excess energy into a second carrier — exactly the multi-carrier escape route real quantum dots rely on to keep cooling fast under practical carrier densities.