Growth of F-doped BaBiO3 thin films via flow-limited field-injection electrostatic spraying toward experimental realization of wide bandgap topological insulator

Abstract

F-doped BaBiO₃ (BBOF), an oxide perovskite predicted theoretically as a wide bandgap topological insulator, is produced in solution phase via flow-limited field-injection electrostatic spraying. BBOF demonstrates insulative properties in optical measurements. Raman spectra indicate the suppression of breathing distortion in BBO due to the electron donation from the substituted fluorine. The F content (α) in the BaBiO_3-αF_α films measured by X-ray photoemission spectroscopy is 0.86. The high F substitution realized in this study contributes to a significant Fermi-level shift, transforming BBO from a high absorption to a transparent phase.