Band alignment and electronic structure of the anatase TiO2/SrTiO3(001) heterostructure integrated on Si(001)
| Autor: | Agham-Bayan S Posadas, Alexander Kvit, Jamal Ramdani, Alexander A. Demkov, Chandrima Mitra, Hosung Seo |
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| Rok vydání: | 2012 |
| Předmět: |
Materials science
business.industry Electron energy loss spectroscopy Lattice (group) Heterojunction Electronic structure Condensed Matter Physics Molecular physics Electronic Optical and Magnetic Materials Scanning transmission electron microscopy Optoelectronics Density functional theory business Electronic band structure Molecular beam epitaxy |
| Zdroj: | Physical Review B. 86 |
| ISSN: | 1550-235X 1098-0121 |
| Popis: | Using density functional theory (DFT), scanning transmission electron microscopy (STEM), and electron energy loss spectroscopy (EELS), we study the interface structure and electronic properties of the anatase-TiO${}_{2}$/SrTiO${}_{3}$(001) heterostructure epitaxially grown on Si(001) by molecular beam epitaxy (MBE). We show that charge transfer at the TiO${}_{2}$/SrTiO${}_{3}$ interface is induced by the chemical bond formation between Ti and O. Subsequent O lattice polarization is found to be the leading screening mechanism at the interface. By comparing the theoretical local electronic structure to the O $K$ edge EELS spectra taken at the interface with atomic resolution, we are able to trace how the local band structure evolves in response to the change in symmetry and bonding across the interface. We also discuss the effect of interfacial point defects (O vacancy and F impurity) on the band alignment. |
| Databáze: | OpenAIRE |
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