title: Epitaxial heterostructures of ultrathin topological insulator nanoplate and graphene.
abstract: The authors present a van der Waals epitaxy of high-quality ultrathin nanoplates of topological insulator Bi(2)Se(3) on a pristine graphene substrate using a simple vapor-phase deposition method. Sub-10-nm-thick nanoplates of layered Bi(2)Se(3) with defined orientations can be epitaxially grown on a few-layer pristine graphene substrate. We show the evolution of Raman spectra with the number of Bi(2)Se(3) layers on few-layer graphene. Bi(2)Se(3) nanoplates with a thickness of three quintuple-layers (3-QL) exhibit the strongest Raman intensity. Strain effects in the Bi(2)Se(3)/graphene nanoplate heterostructures is also studied by Raman spectroscopy. 1-QL and 2-QL Bi(2)Se(3) nanoplates experience tensile stress, consistent with compressive stress in single-layer and bilayer graphene substrates. Our results suggest an approach for the synthesis of epitaxial heterostructures that consist of an ultrathin topological insulator and graphene, which may be a new direction for electronic and spintronic applications.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Center for Nanochemistry, Beijing 100871, People's Republic of China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Dang
authors.forename: Hailin
authors.initials: H
authors.lastname: Peng
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Pu
authors.initials: P
authors.lastname: Wang
authors.forename: Zhongfan
authors.initials: Z
authors.lastname: Liu