Regensburg 2016 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 12: Graphene: Transport
(Joint session of DS, DY, HL, MA, O and TT organized by HL)

TT 12.7: Talk

Monday, March 7, 2016, 17:00–17:15, H17

Influence of disordered edges on transport properties in graphene — Dmitri Smirnov¹, Galina Yu. Vasileva^1,2,3, •Christopher Belke¹, Johannes C. Rode¹, Yurij B. Vasilev², Yurij L. Ivanov², and Rolf J. Haug¹ — ¹Institut fuer Festkoerperphysik, Leibniz Universitaet Hannover — ²Ioffe Institute, Russian Academy of Sciences, St. Petersburg — ³Peter the Great Polytech University, St. Petersburg

The influence of plasma etched edges on electrical transport and doping on graphene devices is studied. Mono- and bilayer samples were fabricated into a specific Hall bar geometry with differing width. The fabrication was done via transfer on a Si/SiO₂ substrate and structuring and contacting via plasma oxygen etching and e-beam lithography. The specific shape allows to investigate the influence of edge disorder on the overall doping and the effective mobility.
The doping concentration, calculated from the charge neutrality point, differs for every region and an inverse dependence on the region width was observed. The sample edge was determined as a strong p-doping source, dominating the bulk doping component and the edge doping contribution and efficiency was obtained.
A further study of the mobility for different regions was used to quantify the edge scattering. We find, that for decreasing region width the mobility decreases as well. This behavior can be attributed to the samples edge, establishing it as a further scattering mechanism.