The development of ultrathin two-dimensional (2D) semiconductor nanostructures have generated considerable interest over the past years. Among these nanostructures, colloidal semiconductor nanoplatelets have a thickness controlled with atomic precision (defined number of monolayers) which leads to strongly tunable and exceptionally narrow optical features . The recent development of II-VI semiconductor heterostructures of various shapes and compositions has allowed to access new optical properties . Here we use femtosecond transient absorption spectroscopy to study the ultrafast dynamics of excitons and charge carriers in CdSe-CdTe core-crown nanoplatelets .
We will also present the current progress in the development of a new two-dimensional electronic spectroscopy setup operating in the visible and ultra-violet range to investigate the sub-100 fs dynamics of colloidal nanocrystals after optical excitation well above the bandgap of the semiconductor nanostructures.
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 E. Cassette, J.C. Dean, G.D. Scholes, Small 2016, 12, 2234.
Collaboration: Elsa Cassette1, Benoît Mahler2, Silvia Pedetti3, Gregory Scholes4
1) LIDYL, UMR 9222 CEA-CNRS-Université Paris-Saclay
2) LM, UMR 5306 Université Claude Bernard, Lyon 1 - CNRS
3) LPEM, UMR 8213 ESPCI-CNRS-UPMC, Paris V
4) Department of Chemistry, Princeton University, USA