Molecular Doping the Topological Dirac Semimetal Na3Bi across the Charge Neutrality Point with F4-TCNQ

Mark T Edmonds; Jack Hellerstedt; Kane M O'Donnell; Anton Tadich; Michael S Fuhrer

doi:10.1021/acsami.6b03312

Molecular Doping the Topological Dirac Semimetal Na3Bi across the Charge Neutrality Point with F4-TCNQ

ACS Appl Mater Interfaces. 2016 Jun 29;8(25):16412-8. doi: 10.1021/acsami.6b03312. Epub 2016 Jun 16.

Authors

Mark T Edmonds¹, Jack Hellerstedt¹, Kane M O'Donnell², Anton Tadich³, Michael S Fuhrer¹

Affiliations

¹ School of Physics and Astronomy and Monash Centre for Atomically Thin Materials, Clayton Victoria 3800, Australia.
² Department of Imaging and Applied Physics, Curtin University , Bentley, Western Australia 6102, Australia.
³ Australian Synchrotron , 700 Blackburn Road, Clayton, Victoria 3168, Australia.

PMID: 27309858
DOI: 10.1021/acsami.6b03312

Abstract

We perform low-temperature transport and high-resolution photoelectron spectroscopy on 20 nm thin film topological Dirac semimetal Na3Bi grown by molecular beam epitaxy. We demonstrate efficient electron depletion ∼10(13) cm(-2) of Na3Bi via vacuum deposition of molecular F4-TCNQ without degrading the sample mobility. For samples with low as-grown n-type doping (1 × 10(12) cm(-2)), F4-TCNQ doping can achieve charge neutrality and even a net p-type doping. Photoelectron spectroscopy and density functional theory are utilized to investigate the behavior of F4-TCNQ on the Na3Bi surface.

Keywords: Na3Bi; surface transfer doping; thin film; topological Dirac semimetal.