Thursday, February 7, 2013

1302.1310 (Guang-Xin Ni et al.)

Quasi-Periodic Nanoripples in Graphene Grown by Chemical Vapor
Deposition and Its Impact on Charge Transport
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Guang-Xin Ni, Yi Zheng, Sukang Bae, Hye Ri Kim, Alexandre Pachoud, Young Soo Kim, Chang-Ling Tan, Danho Im, Jong-Hyun Ahn, Byung Hee Hong, Barbaros Özyilmaz
The technical breakthrough in synthesizing graphene by chemical vapor deposition methods (CVD) has opened up enormous opportunities for large-scale device applications. In order to improve the electrical properties of CVD graphene grown on copper (Cu-CVD graphene), recent efforts have focussed on increasing the grain size of such polycrystalline graphene films to 100 micrometers and larger. While an increase in grain size and hence, a decrease of grain boundary density is expected to greatly enhance the device performance, here we show that the charge mobility and sheet resistance of Cu-CVD graphene is already limited within a single grain. We find that the current high-temperature growth and wet transfer methods of CVD graphene result in quasi-periodic nanoripple arrays (NRAs). Electron-flexural phonon scattering in such partially suspended graphene devices introduces anisotropic charge transport and sets limits to both the highest possible charge mobility and lowest possible sheet resistance values. Our findings provide guidance for further improving the CVD graphene growth and transfer process.
View original: http://arxiv.org/abs/1302.1310

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