title: Organic Monolayer Protected Topological Surface State.
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.
authors.forename: Hung-Hsiang
authors.initials: HH
authors.lastname: Yang
authors.forename: Yu-Hsun
authors.initials: YH
authors.lastname: Chu
authors.forename: Chun-I
authors.initials: CI
authors.lastname: Lu
authors.forename: Christopher John
authors.initials: CJ
authors.lastname: Butler
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 10617, Taiwan.
authors.forename: Raman
authors.initials: R
authors.lastname: Sankar
authors.affiliation: National Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan.|Taiwan Consortium of Emergent Crystalline Materials (TCECM), Ministry of Science and Technology , Taipei 10622, Taiwan.
authors.forename: Fang-Cheng
authors.initials: FC
authors.lastname: Chou
authors.affiliation: Institute of Atomic and Molecular Sciences, Academia Sinica , Taipei 10617, Taiwan.
authors.forename: Minn-Tsong
authors.initials: MT
authors.lastname: Lin
keywords: Scanning tunneling microscopy; charge transfer; organic tunneling barrier; scanning tunneling spectroscopy; self-assembled molecular layer; topological insulator