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From nanoscale ultrafast optoelectronics to trapped dipolar excitons - A.W. Holleitner - Lundi 21 novembre 2016 à 14 h

INSP - UPMC - 4 place Jussieu - 75005 Paris - Barre 22-32, 2e étage, salle 201

A.W. Holleitner - Walter Schottky Institut and Physics Department, Technical University of Munich (TUM), Germany.


As electronic circuits reach the nanometer length scale, it is essential to study the charge and heat dynamics in nanomaterials, such as graphene, transition metal dichalcogenides, and semiconductor nanowires, which can be integrated into future information circuits. We apply an ultrafast photocurrent spectroscopy to detect on-chip the electron dynamics in nanoscale circuits with a sub-picosecond time-resolution [1,2]. The ultrafast detection gives access to the time-of-flight of photogenerated charge carriers as well as non-equilibrium thermo-electric currents, and non-radiative energy transfer processes [3]. In my presentation, I will give an introduction to the experimental scheme and to ultrafast electron dynamics inherent to the different nano-morphologies [4]. In particular, I highlight the interplay of the exciton dissociation and the ultrafast ballistic propagation of the electrons and holes [5]. Moreover, I present our most recent advances in trapping single dipolar excitons in nanoscale circuits. [1] L. Prechtel, et al. Nature Comm. 3, 646 (2012).
[2] C. Kastl, et al. Nature Comm. 6, 6617 (2015).
[3] A. Brenneis, et al. Nature Nano. 10, 135 (2015).
[4] A. Brenneis, et al. Sci Rep. 6, 35654 (2016).
[5] C. Karnetzky, et al. submitted.