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TT: Fachverband Tiefe Temperaturen
TT 22: Graphene: Fabrication
(Joint session of DS, DY, HL, MA, O and TT organized by HL)
TT 22.2: Talk
Monday, March 7, 2016, 18:00–18:15, H17
Optoelectronic Properties of Graphene Nano-Ribbons Patterned By Helium Ion Beam Lithography — •Akshay Kumar Mahadev Arabhavi1, Andreas Brenneis1,2, Simon Drieschner1,2, Marcus Altzschner1, Helmut Karl3, Jose Garrido1,2, and Alexander Holleitner1,2 — 1Walter Schottky Institut and Physics-Department, Technical University Munich, Am Coulombwall 4a, 85748 Garching, Germany. — 2Nanosystems Initiative Munich (NIM), Schellingstr. 4, 80799 Munich, Germany. — 3Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.
High electron mobility, excellent thermal conductivity and uniform absorption in the visible range makes graphene an outstanding material for high-frequency optoelectronic applications. However, the lack of a band gap limits graphene in switching applications. A quantization energy can be introduced by confining graphene to one-dimensional ribbons of widths below 20 nm, for instance, using Helium Ion Beam Lithography (HIBL) [1-2]. We have optimized the parameters to pattern graphene nano-ribbons on sapphire substrates using HIBL, such as dose, beam current, spot control and dwell time. Moreover, we apply an ultrafast photocurrent spectroscopy [3] to investigate the optoelectronic properties of the patterned graphene nano-ribbons with respect to their high-frequency properties. References: [1] M. Han et al., Phys. Rev. Lett. 98, 206805, (2007). [2] Bell DC et al., Nanotechnology 20, 455301, (2009). [3] A. Brenneis, et al., Nature Nanotech, 10, 135, (2015).