Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 78: Graphene: Electronic Properties (organized by O)

TT 78.13: Vortrag

Mittwoch, 2. April 2014, 19:00–19:15, WIL C107

Controlling and understanding the non-linear photoluminescence in graphene on a femtosecond time scale — •Richard Ciesielski¹, Alberto Comin¹, Matthias Handloser¹, Kevin Donkers¹, Torben Winzer², Ermin Malic², and Achim Hartschuh¹ — ¹Ludwig Maximilians Universität München & CeNS — ²TU Berlin

Upon excitation, graphene exhibits nonlinear photoluminescence [1-3] that reflects the charge-carrier population and relaxation around the K-point. We present microscopic measurements on high quality exfoliated graphene samples with a pulsed laser system of ca. 18fs and a broad spectrum centred at 800nm.

Using a pulse shaping setup we can measure and manipulate the incident pulse in amplitude and phase. We find that the PL intensity depends sensitively on the temporal shape of the laser pulse, which we use to study and control the charge-carrier relaxation processes of graphene. Our findings are compared to numerical calculations.

[1] Stöhr, Wachtrup, Phys. Rev. B 82, 121408(R) (2010)

[2] Malic, Winzer, Bobkin, Knorr, Phys. Rev. B 84, 205404 (2011)

[3] Malic, Knorr, John Wiley & Sons (2013)