🔬 Quantum Dots — Size-Tunable Fluorescence
Explore quantum confinement in semiconductor nanocrystals. Adjust dot size to see how the Brus equation E = E_bulk + ℏ²π²/(2μr²) shifts emission wavelength, turning tiny crystals from red to blue as they shrink.
4.0 nm
12
300 K
0.70
The Physics
The Brus equation predicts confinement energy: E_conf = ℏ²π²/(2r²) · (1/m_e* + 1/m_h*). Emission wavelength λ = hc/E_total. As radius r decreases, E_conf ∝ 1/r² grows, blue-shifting emission. CdSe dots (2–8 nm) span 460–650 nm — the entire visible spectrum tuned purely by size.