Topological Surface State of Bi2Se3 Modified by Physisorption of n‐Alkane. Issue 3 (24th January 2023)

• Record Type: Journal Article
• Authors: Moue, Rena; Yamazaki, Hiroto; Kitazawa, Tatsuya; Yaji, Koichiro; Yaguchi, Hiroshi; Kuroda, Kenta; Kondo, Takeshi; Harasawa, Ayumi; Iwahashi, Takashi; Ouchi, Yukio; Shin, Shik; Kanai, Kaname
• Is Part Of: ChemNanoMat. Volume 9:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-24
• Subjects: topological insulators -- Bi2Se3 -- tetratetracontane -- physisorption, interfacial electronic structure; Nanochemistry -- Periodicals; Nanostructured materials -- Periodicals; Nanochemistry; Nanostructured materials; Periodicals; 541.2
• DOI: 10.1002/cnma.202200538
• Languages: English
• ISSNs: 2199-692X

Abstract

Abstract: Recently, the interface between an organic molecular layer and a topological insulator (TI) surface (Org./TI interface) has been studied to explore the possibility of multifunctional TI devices with organic molecules. Nevertheless, understanding of the electronic structure of Org./TI interfaces is insufficient. Especially, little is known about physisorption systems, where the interaction between adsorbed molecules and topological surface state (TSS) is weak. Here, we discuss an ideal physisorption system of an n ‐alkane molecule, n ‐tetratertacontane (TTC), and prototypical TI, Bi2 Se3, in which the interaction between the molecule and TSS is the weakest one possible. Angle‐resolved photoemission spectroscopy results show that the energy of the Dirac cone (DC) energy band decreases by approximately 60 meV when the TTC layer is formed on Bi2 Se3 . The amount of energy reduction is consistent with the reduction in vacuum level at the TTC/Bi2 Se3 interface, valence states of Bi2 Se3 and the core levels of Bi2 Se3 observed by ultraviolet‐ and X‐ray photoemission spectroscopy. Therefore, no chemical interactions, such as charge transfer, occur at the TTC/Bi2 Se3 interface, but only a redistribution of charge density on the Bi2 Se3 surface occurs due to the Pauli repulsion between the electrons of the adsorbed TTC molecule and TSS. Abstract : n ‐Tetratertacontane (TTC) is physisorbed on the prototype topological insulator Bi2 Se3 surface. Angle‐resolved photoemission spectroscopy measurements show that the formation of a TTC layer on Bi2 Se3 leads to a change in the topological surface state with an energy shift in the Dirac cone dispersion.