Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 39: Graphene: Characterization and Devices (jointly with DS, HL, MA, and TT)
O 39.9: Vortrag
Mittwoch, 13. März 2013, 11:45–12:00, H17
Broadband THz detection with graphene flakes — •Martin Mittendorff1,2, Stephan Winnerl1, Josef Kamann3, Jonathan Eroms3, Harald Schneider1, and Manfred Helm1,2 — 1Helmholtz-Zentrum Dresden-Rossendorf, Germany — 2Universität Dresden, Germany — 3Universität Regensburg, Germany
We demonstrate a broadband THz detector based on graphene flakes, which are produced by scotch-tape method on SiO2/Si, combined with a logarithmic periodic antenna. The antenna is coupled to the graphene flake with an interdigitated comb-like structure in the center. The detectors were characterized at roomtemperature using the free-electron laser FELBE at the Helmholtz-Zentrum Dresden-Rossendorf. The responsivity is above 1 nA/W for wavelengths from 30 µ m to 220 µ m. The rise time of the measured signals is below 100 ps and their length is in the range of 200 ps, while the pulse duration of the FEL pulses is around 20ps. The effect of the antenna coupling could be confirmed via polarization dependent measurements. Due to the spectral bandwidth combined with high temporal resolution and simple handling these detectors can be very useful for timing purposes of short laser pulses.