Format

Send to

Choose Destination
Nano Lett. 2016 Mar 9;16(3):1989-95. doi: 10.1021/acs.nanolett.5b05263. Epub 2016 Feb 15.

van der Waals Heterostructures with High Accuracy Rotational Alignment.

Author information

1
Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78758, United States.
2
Physics Department, University of Arizona , Tucson, Arizona 85721, United States.
3
National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan.

Abstract

We describe the realization of van der Waals (vdW) heterostructures with accurate rotational alignment of individual layer crystal axes. We illustrate the approach by demonstrating a Bernal-stacked bilayer graphene formed using successive transfers of monolayer graphene flakes. The Raman spectra of this artificial bilayer graphene possess a wide 2D band, which is best fit by four Lorentzians, consistent with Bernal stacking. Scanning tunneling microscopy reveals no moiré pattern on the artificial bilayer graphene, and tunneling spectroscopy as a function of gate voltage reveals a constant density of states, also in agreement with Bernal stacking. In addition, electron transport probed in dual-gated samples reveals a band gap opening as a function of transverse electric field. To illustrate the applicability of this technique to realize vdW heterostructuctures in which the functionality is critically dependent on rotational alignment, we demonstrate resonant tunneling double bilayer graphene heterostructures separated by hexagonal boron-nitride dielectric.

KEYWORDS:

Two-dimensional; boron-nitride; graphene; heterostructure; resonant tunneling

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center