Colloidal semiconductor nanocrystals (NCs) have emerged as a family of materials with size-dependent optical and electronic properties. Combined with their capability for wet-chemical processing, this has led to NC-based light-emitting diodes, solar cells, and transistor devices. It is then of crucial importance to have a clear understanding of the optical and electronic properties caused by quantum –size phenomena.

In this talk, we report magneto-optical and time-resolved spectroscopic investigations of single CdSe/ZnS nanocrystals as a function of temperature. Because of the nanocrystal shape distribution, we find various band-edge exciton and biexciton fine structures that are consistent with theoretical predictions for elongated NCs. Furthermore, contrarily to what was anticipated for “standard” CdSe-based core shell NCs, we present here the spectral and temporal signatures of highly efficient radiative biexcitonic recombinations for this type of NCs.

Our latest result is the study of the magneto-optical properties of trions resulting in the direct determination of the electron and hole g-factors.


Wednesday, March 21, 2012, 17:00. Seminar Room