Synthesis and properties of crystalline thin film of antimony trioxide on the Si(100) substrate

•Formation of crystalline phase of Sb2O3 on Si(100) is demonstrated.•STM and STS characterizations of the grown Sb2O3 film are presented.•STS results elucidate the band gap of Sb2O3.•Ab initio calculations reveal energetically favored Sb2O3 surface structures. Atomic-scale understanding and processing of the surface and interface properties of antimony trioxide (Sb2O3) are essential to the development of nanoscale Sb2O3 materials for various applications, such as photocatalysts, transparent conducting oxides, optical coatings, dielectric films, and fire retardants. Lack of atomically well-defined, crystalline Sb2O3 templates has however hindered atomic resolution characterization of the Sb2O3 properties. We report the preparation of crystalline Sb2O3 thin films on the Si(100) substrate with a simple process by oxidizing Sb-covered Si(100) in proper conditions. Physical properties of the synthesized films have been elucidated by low-energy electron diffraction, scanning tunneling microscopy and spectroscopy, and ab initio calculations. The spectroscopic results show that the band gap of Sb2O3 is 3.6eV around the gamma point (i.e. Γ). Calculations reveal energetically favored Sb2O3(100) surface structures. The findings open a new path for the atomic-scale research of Sb2O3.