Organic Monolayer Protected Topological Surface State

Hung-Hsiang Yang; Yu-Hsun Chu; Chun-I Lu; Christopher John Butler; Raman Sankar; Fang-Cheng Chou; Minn-Tsong Lin

doi:10.1021/acs.nanolett.5b02811

Organic Monolayer Protected Topological Surface State

Nano Lett. 2015 Oct 14;15(10):6896-900. doi: 10.1021/acs.nanolett.5b02811. Epub 2015 Sep 24.

Authors

Hung-Hsiang Yang, Yu-Hsun Chu, Chun-I Lu, Christopher John Butler, Raman Sankar¹, Fang-Cheng Chou^{2

3}, Minn-Tsong Lin¹

Affiliations

¹ Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 10617, Taiwan.
² National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan.
³ Taiwan Consortium of Emergent Crystalline Materials (TCECM), Ministry of Science and Technology , Taipei 10622, Taiwan.

PMID: 26393876
DOI: 10.1021/acs.nanolett.5b02811

Abstract

Perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA)/Bi2Se3 and Fe/PTCDA/Bi2Se3 heterointerfaces are investigated using scanning tunneling microscopy and spectroscopy. The close-packed self-assembled PTCDA monolayer possesses big molecular band gap and weak molecule-substrate interactions, which leaves the Bi2Se3 topological surface state intact under PTCDA. Formation of Fe-PTCDA hybrids removes interactions between the Fe dopant and the Bi2Se3 surface, such as doping effects and Coulomb scattering. Our findings reveal the functionality of PTCDA to prevent dopant disturbances in the TSS and provide an effective alternative for interface designs of realistic TI devices.

Keywords: Scanning tunneling microscopy; charge transfer; organic tunneling barrier; scanning tunneling spectroscopy; self-assembled molecular layer; topological insulator.

Publication types

Research Support, Non-U.S. Gov't