Intraband transitions in semiconductor nanocrystals

Abstract

Intraband spectra of CdSe nanocrystal colloids are observed. The photoexcited nanocrystals, of average diameters 31.5, 38, and 43 Å, exhibit an isolated and strong infrared-induced absorption with peak energy between 0.5 and 0.3 eV. The energies and cross sections of the resonance are consistent with a one-electron transition between the delocalized 1Se and 1Pe states of the strongly confined quantum dots.