Dresden 2026 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 42: Electronic structure of surfaces: Spectroscopy, surface states – Poster
O 42.4: Poster
Tuesday, March 10, 2026, 14:00–16:00, P2
Chiral-Induced Spin Selectivity in Thia-Bridged Triarylamine Hetero[4]helicenes SAMs: Structural Insights from XPS and NEXAFS — •Yichen Jin1, Jan Böhnke1, Lapo Querci2, Niccolò Giaconi2, Cornelius Gahl1, Dominik Stemer3, Roberta Sessoli2, Matteo Mannini2, and Martin Weinelt1 — 1Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany — 2University of Florence, Via della Lastruccia 3-13, Sesto Fiorentino 50019, Italy — 3Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
Helicene enantiomers act as efficient spin filters when assembled on metallic surfaces, making them promising candidates for organic spintronic applications. Previous magnetic conductive AFM studies reported spin polarizations of up to ~60% through the respective chiral enantiomers of Thia-Bridged Triarylamine Hetero[4]helicenes (HelSAc) self-assembled monolayers (SAMs) ascribed to the chirality-induced spin selectivity (CISS) effect. To understand the structural origins underlying this behavior, we investigated HelSAc SAMs on Au(111) using XPS and NEXAFS. Angle-dependent XP spectra of sulphur 2p reveal three chemically distinct components assigned to S*C, S*Au, and atomic sulfur. NEXAFS shows pronounced polarization dependences of the σ* and π* resonances, demonstrating the parallel alignment of the HelSAc to the Au surface. Together, these results establish a well-defined chemical and structural picture of HelSAc SAMs, providing the essential foundation for interpreting spin-dependent photoelectron spectroscopy and understanding the CISS effect in this chiral system.
Keywords: Self-assembled monolayers; Helicene enantiomers; Angle-dependent XP spectra; Molecular orientation; Chirality-induced spin selectivity effect