L. Banszerus1, M. Schmitz1, S. Engels1,2, J. Dauber1,2, M. Oellers1, F. Haupt3, K. Watanabe4, T. Taniguchi4, B. Beschoten1 and C. Stampfer1,2

1 JARA-FIT and 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany, EU
2 Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, 52425 Jülich, Germany, EU
3 JARA-Institute for Quantum Information, RWTH Aachen University, 52056 Aachen, Germany, EU
4 National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan


Over the past years many promising applications of graphene have been demonstrated on individual devices. In order to advance from basic research towards scalable industrial applications, large area high quality graphene is needed. One promising approach to achieve this is chemical vapor deposition of graphene on copper [1]. However, so far the charge carrier mobility of CVD grown graphene has been significantly lower than what has been observed in devices fabricated from exfoliated graphene [2]. In this work we show that the electronic quality of CVD graphene depends critically on the transfer method and we present a novel dry transfer technique for CVD-grown graphene crystals that yields devices encapsulated in hexagonal boron nitride (hBN) with mobilities up to 350,000 cm2/Vs. In addition to the diffusive transport in such samples, we demonstrate an elastic mean free path exceeding one micrometer at temperatures of up to 200 K using Hall cross devices [3].

[1] X. Li et al., Science 324, 1312 (2009).
[2] N. Petrone et al., Nano Letters 12, 2751 (2012).
[3] S. Mayorov et al., Nano Letters 11 2396 (2011)

Luca Banszerus is currently a Master’s student in the group of Christoph Stampfer at RWTH Aachen University in Germany. He is working on CVD growth of graphene and the transfer of the graphene from the growth substrate to arbitrary substrates.