Simulating Excitons and Multiexcitons under Confinement

Semiconductor nanocrystals (NCs) are small bright light-emitting particles containing thousands of atoms and tens of thousands of valence electrons with discrete spectra at low excitation energies similar to molecules that converge to the continuum bulk limit at higher energies. Due to the quantum confinement effect, a spatial enclosure of the charge carriers (electrons, holes, excitons, etc.) within the NC, the electronic and optical properties can be tuned by simply changing the size and shape of the NCs, in addition to changing the material composition. Significant progress in developing a broad range of applications-based NC devices utilizing the quantum confinement in solar energy conversion, optoelectronic devices, molecular and cellular imaging, and ultrasensitive detection, has been hampered by the lack of a deeper understanding of the carrier dynamics under confinement.