Study of the radiative recombination processes in tetrapod-shaped CdTe nanocrystals

In this work we report the time dependence emission properties of photoexcited carriers in CdTe tetrapod nanocrystals, by using time-resolved photoluminescence spectroscopy. The emission dynamics of the ground and excited state of a tetrapod-structure have pointed out different temporal behaviours ascribed to different carrier relaxation mechanisms. By monitoring the transient emission spectra at different delay times, a remarkable change in the energy position of the lower energy state has been observed, attributable to a photoinduced screening of an internal electric field, originating, in turn, from the ground state charge separation.