• Sanderson, David
• Kretinin, Andrey V.
• Guo, Jianqiang
• Xiang, Ying
• Wang, Zhiyuan
• Mao, Boyang
• Tovari, Endre
• Falko, Vladimir I.
• Spencer, Ben Felix
• Slizovskiy, Sergey
• Geim, Alexandra
• Gudarzi, Mohsen Moazzami
• Asaad, Maryana
• Pinter, Gergo

Abstract

Understanding and controlling the electrical properties of solution-processed 2D<br/>materials is key to further printed electronics progress. Here we demonstrate that the thermolysis of the aromatic intercalants utilized in nanosheet exfoliation for graphene laminates opens the route to achieving high intrinsic mobility and simultaneously controlling doping type (n- and p-) and concentration over a wide range. We establish that the intra-flake mobility is high by observing a linear magnetoresistance of such solution-processed graphene laminates and using it to devolve the inter-flake tunneling and intra-layer magnetotransport. Consequently, we determine the temperature dependencies of the inter- and intra-layer characteristics. The intra-flake transport appears to be dominated by electron-phonon scattering processes at temperatures&gt; 20 Kelvin, while the inter-flake transport is governed by phonon-assisted tunneling. In particular, we identify the efficiency of phonon-assisted tunneling as the main limiting factor for electrical conductivity in graphene laminates at room temperature. We also demonstrate a thermoelectric sensitivity of around 50 μV·K–1 in a solution-processed metal-free graphene-based thermocouple.

Topics

• impedance spectroscopy
• mobility
• electrical conductivity
• thermolysis