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Charge transport and electron-hole asymmetry in low-mobility graphene/hexagonal boron nitride heterostructures

Li, Jiayu; Lin, Li; Huang, Guang Yao; Kang, N.; Zhang, Jincan; Peng, Hailin; Liu, Zhongfan and Xu, H. Q. LU (2018) In Journal of Applied Physics 123(6).
Abstract

Graphene/hexagonal boron nitride (G/h-BN) heterostructures offer an excellent platform for developing nanoelectronic devices and for exploring correlated states in graphene under modulation by a periodic superlattice potential. Here, we report on transport measurements of nearly 0°-twisted G/h-BN heterostructures. The heterostructures investigated are prepared by dry transfer and thermally annealing processes and are in the low mobility regime (approximately 3000 cm2 V-1s-1 at 1.9 K). The replica Dirac spectra and Hofstadter butterfly spectra are observed on the hole transport side, but not on the electron transport side, of the heterostructures. We associate the observed electron-hole asymmetry with the... (More)

Graphene/hexagonal boron nitride (G/h-BN) heterostructures offer an excellent platform for developing nanoelectronic devices and for exploring correlated states in graphene under modulation by a periodic superlattice potential. Here, we report on transport measurements of nearly 0°-twisted G/h-BN heterostructures. The heterostructures investigated are prepared by dry transfer and thermally annealing processes and are in the low mobility regime (approximately 3000 cm2 V-1s-1 at 1.9 K). The replica Dirac spectra and Hofstadter butterfly spectra are observed on the hole transport side, but not on the electron transport side, of the heterostructures. We associate the observed electron-hole asymmetry with the presence of a large difference between the opened gaps in the conduction and valence bands and a strong enhancement in the interband contribution to the conductivity on the electron transport side in the low-mobility G/h-BN heterostructures. We also show that the gaps opened at the central Dirac point and the hole-branch secondary Dirac point are large, suggesting the presence of strong graphene-substrate interaction and electron-electron interaction in our G/h-BN heterostructures. Our results provide additional helpful insight into the transport mechanism in G/h-BN heterostructures.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Applied Physics
volume
123
issue
6
publisher
American Institute of Physics
external identifiers
  • scopus:85042067895
ISSN
0021-8979
DOI
10.1063/1.5009742
language
English
LU publication?
yes
id
047e2431-8980-4778-a608-f17cfdcce261
date added to LUP
2018-03-06 12:10:36
date last changed
2018-05-29 09:43:43
@article{047e2431-8980-4778-a608-f17cfdcce261,
  abstract     = {<p>Graphene/hexagonal boron nitride (G/h-BN) heterostructures offer an excellent platform for developing nanoelectronic devices and for exploring correlated states in graphene under modulation by a periodic superlattice potential. Here, we report on transport measurements of nearly 0°-twisted G/h-BN heterostructures. The heterostructures investigated are prepared by dry transfer and thermally annealing processes and are in the low mobility regime (approximately 3000 cm<sup>2</sup> V<sup>-1</sup>s<sup>-1</sup> at 1.9 K). The replica Dirac spectra and Hofstadter butterfly spectra are observed on the hole transport side, but not on the electron transport side, of the heterostructures. We associate the observed electron-hole asymmetry with the presence of a large difference between the opened gaps in the conduction and valence bands and a strong enhancement in the interband contribution to the conductivity on the electron transport side in the low-mobility G/h-BN heterostructures. We also show that the gaps opened at the central Dirac point and the hole-branch secondary Dirac point are large, suggesting the presence of strong graphene-substrate interaction and electron-electron interaction in our G/h-BN heterostructures. Our results provide additional helpful insight into the transport mechanism in G/h-BN heterostructures.</p>},
  articleno    = {064303},
  author       = {Li, Jiayu and Lin, Li and Huang, Guang Yao and Kang, N. and Zhang, Jincan and Peng, Hailin and Liu, Zhongfan and Xu, H. Q.},
  issn         = {0021-8979},
  language     = {eng},
  month        = {02},
  number       = {6},
  publisher    = {American Institute of Physics},
  series       = {Journal of Applied Physics},
  title        = {Charge transport and electron-hole asymmetry in low-mobility graphene/hexagonal boron nitride heterostructures},
  url          = {http://dx.doi.org/10.1063/1.5009742},
  volume       = {123},
  year         = {2018},
}