Self-assembly of electronically abrupt borophene/organic lateral heterostructures

Xiaolong Liu; Zonghui Wei; Itamar Balla; Andrew J Mannix; Nathan P Guisinger; Erik Luijten; Mark C Hersam

doi:10.1126/sciadv.1602356

Self-assembly of electronically abrupt borophene/organic lateral heterostructures

Sci Adv. 2017 Feb 22;3(2):e1602356. doi: 10.1126/sciadv.1602356. eCollection 2017 Feb.

Authors

Xiaolong Liu¹, Zonghui Wei¹, Itamar Balla², Andrew J Mannix³, Nathan P Guisinger⁴, Erik Luijten⁵, Mark C Hersam⁶

Affiliations

¹ Applied Physics Graduate Program, Northwestern University, Evanston, IL 60208, USA.
² Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.
³ Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.; Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA.
⁴ Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA.
⁵ Applied Physics Graduate Program, Northwestern University, Evanston, IL 60208, USA.; Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.; Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208, USA.; Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208, USA.
⁶ Applied Physics Graduate Program, Northwestern University, Evanston, IL 60208, USA.; Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA.; Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.; Department of Electrical Engineering and Computer Science, Northwestern University, Evanston, IL 60208, USA.

Abstract

Two-dimensional boron sheets (that is, borophene) have recently been realized experimentally and found to have promising electronic properties. Because electronic devices and systems require the integration of multiple materials with well-defined interfaces, it is of high interest to identify chemical methods for forming atomically abrupt heterostructures between borophene and electronically distinct materials. Toward this end, we demonstrate the self-assembly of lateral heterostructures between borophene and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA). These lateral heterostructures spontaneously form upon deposition of PTCDA onto submonolayer borophene on Ag(111) substrates as a result of the higher adsorption enthalpy of PTCDA on Ag(111) and lateral hydrogen bonding among PTCDA molecules, as demonstrated by molecular dynamics simulations. In situ x-ray photoelectron spectroscopy confirms the weak chemical interaction between borophene and PTCDA, while molecular-resolution ultrahigh-vacuum scanning tunneling microscopy and spectroscopy reveal an electronically abrupt interface at the borophene/PTCDA lateral heterostructure interface. As the first demonstration of a borophene-based heterostructure, this work will inform emerging efforts to integrate borophene into nanoelectronic applications.

Keywords: Boron; Molecular Dynamics; PTCDA; Scanning tunneling microscopy; Two-dimensional; X-ray photoelectron spectroscopy; borophene; heterostructure; organic; self-assembly.

Grants and funding

P30 CA060553/CA/NCI NIH HHS/United States