Size-dependent electron-hole exchange interaction in Si nanocrystals

Nano-engineered electron–hole exchange interaction controls exciton dynamics in core–shell semiconductor nanocrystals

A strong electron-hole exchange interaction (EI) in semiconductor nanocrystals (NCs) gives rise to a large (up to tens of meV) splitting between optically active ('bright') and optically passive ('dark') excitons. This dark-bright splitting has a significant effect on the optical properties of band-edge excitons and leads to a pronounced temperature and magnetic field dependence of radiative de...

Raman scattering by electron-hole excitations in silver nanocrystals

Raman scattering experiments from silver nanocrystals embedded in films of amorphous silica are reported. In addition to the low-frequency peak due to vibrational quadrupolar modes, a broadband is observed in the high-frequency range, with a maximum at about 1000 cm. The linear dependence of the position of this maximum on the inverse cluster radius is in agreement with the Raman scattering by ...

Size dependent carrier recombination in ZnO nanocrystals

Mapping of few-electron wave-functions in semiconductor nanocrystals - evidence of exchange interaction

The influence of the tip-substrate bias induced electric field in a scanningtunneling-spectroscopy experiment on charged InAs nanocrystals is studied. Calculating the ground and first excited many-particle state for five electrons occupying the quantum dot reveals a Stark-induced reordering of states by increasing the electric field strength. It is shown that this reordering of states is accomp...

Commentary: Carbon nanotubes, CdSe nanocrystals, and electron-electron interaction.

To celebrate the tenth anniversary of Nano Letters, this short commentary discusses a scientific issue of current interest, increased electron-electron interactions in nanostructures. The two major factors of reduced dimensionality and low screening are analyzed. Carbon nanotubes and graphene are molecular in many of their properties and show strong electron-electron interactions. In specific c...