Accession Number : AD1015572

Title :   Rotationally Commensurate Growth of MoS2 on Epitaxial Graphene

Descriptive Note : Journal Article

Corporate Author : Northwestern University Evanston United States

Personal Author(s) : Liu,Xiaolong ; Balla,Itamar ; Bergeron,Hadallia ; Campbell,Gavin P ; Bedzyk,Michael J ; Hersam,Mark C

Full Text :

Report Date : 13 Nov 2015

Pagination or Media Count : 9

Abstract : Atomically thin MoS2/graphene heterostructures are promising candidates for nanoelectronic and optoelectronic technologies. Among different graphene substrates, epitaxial graphene (EG) on SiC provides several potential advantages for such heterostructures, including high electronic quality, tunable substrate coupling, wafer-scale processability, and crystalline ordering that can template commensurate growth. Exploiting these attributes, we demonstrate here the thickness controlled van der Waals epitaxial growth of MoS2 on EG via chemical vapor deposition, giving rise to transfer-free synthesis of a two-dimensional heterostructure with registry between its constituent materials. The rotational commensurability observed between theMoS2 and EG is driven by the energetically favorable alignment of their respective lattices and results in nearly strain-free MoS2, as evidenced by synchrotron X-ray scattering and atomic resolution scanning tunneling microscopy (STM). The electronic nature of the MoS2/EG heterostructure is elucidated with STM and scanning tunneling spectroscopy, which reveals bias-dependent apparent thickness, band bending, and a reduced band gap of 0.4 eV at the monolayer MoS2 edges.

Descriptors :   epitaxial growth , GRAPHENE , MOLYBDENUM COMPOUNDS , transition metals , silicon compounds , SYNCHROTRON RADIATION , X RAY SCATTERING , chemical vapor deposition , substrates , thickness , Raman spectroscopy , band gaps , density functional theory , CONDUCTION BANDS , valence bands , microscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE