Berlin 2015 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 59: Graphene: Applications, luminescence and spin relaxation (HL with O/TT)

HL 59.7: Vortrag

Mittwoch, 18. März 2015, 18:15–18:30, ER 270

Polarised Hot Carrier Photoluminescence in Graphene — •Thomas Danz, Andreas Neff, Reiner Bormann, Sascha Schäfer, and Claus Ropers — 4th Physical Institute, University of Göttingen, Göttingen, Germany

The thermalisation of photogenerated hot charge carriers in graphene leads to photoluminescence at wavelengths far away from that of the exciting pump laser [1,2]. To date, no polarisation properties of the photoluminescence have been reported, although recent numerical simulations show a strong anisotropy of the underlying relaxation processes in graphene [3]. This is in agreement with the results of transient pump-probe measurements showing a dependence of the transmissivity on the angle between pump and probe polarisations [4]. Here, we present polarisation- und time-resolved two-pulse excitation photoluminescence measurements with sub-30fs ultrashort laser pulses. We demonstrate an anisotropic nature of the emitted photoluminescence and use these findings to discuss complementary insights into the ultrafast carrier response in graphene.

[1] C. H. Lui et al., Phys. Rev. Lett. 105, 127404 (2010)

[2] W. Liu et al., Phys. Rev. B. 82, 081408 (2010)

[3] E. Malic et al., Appl. Phys. Lett. 101, 213110 (2012)

[4] M. Mittendorff et al., Nano Lett. 14, 1504 (2014)