Surface-driven structural evolution and electronic transition of SbSe chains on Au(111)

Low-dimensional materials have attracted significant attention due to their unique physical properties and broad potential applications. Antimony selenide is well known for its thermoelectric properties. However, the on-surface synthesis of chain-like structures with varying stoichiometries remains challenging. In this study, we employ scanning tunneling microscopy/spectroscopy and density functional theory calculations to investigate the epitaxial growth of SbSe chain structures. With increasing deposition of Sb and Se, a transition is observed in both the structural and electronic properties, shifting from semiconducting mixed chains to metallic uniform tri-chains. X-ray photoelectron spectroscopy confirms the elemental composition and helps determine the stoichiometries. Theoretical calculations show that the mixed-chain phase is an indirect bandgap semiconductor with a bandgap of 0.17 eV, and that spin–orbit coupling induces band splitting. In contrast, the tri-chain phase, formed by weak van der Waals interactions between chains within the unit cell, undergoes a semiconductor-to-metal transition due to strong hybridization near the Fermi level. These findings not only provide a strategy for tuning the electronic properties of one-dimensional materials but also provide valuable insights for the design of thermoelectric and quantum materials, with potential applications in next-generation electronic devices.