First principle study of Nb defects in anatase (101) TiO2 surface
| Autor: | Alireza Sasani, Azadeh Alavizargar, Kavoos Mirabbaszadeh, Ardeshir Baktash |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Anatase Work (thermodynamics) Materials science Condensed matter physics Band gap Mechanical Engineering Doping technology industry and agriculture Niobium chemistry.chemical_element 02 engineering and technology Electronic structure Crystal structure 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences chemistry Mechanics of Materials Computational chemistry 0103 physical sciences General Materials Science Density functional theory 0210 nano-technology |
| Zdroj: | Materials Science in Semiconductor Processing. 45:45-50 |
| ISSN: | 1369-8001 |
| Popis: | In this work, effects of Niobium (Nb) defects on TiO 2 surface using density functional theory (DFT) are investigated. Based on formation energy of the defects, their occurrences in two different extreme conditions, O-rich and O-poor conditions, are evaluated. Effects of Nb defects on surface and its electronic structure are studied and it is demonstrated that Nb doping widens valence band in deep energy level leaving the band gap without any change and it also lowers oxygen vacancy defect concentration due to the stronger bonding of Nb sub defect with oxygen atoms specially bridging oxygen (most probable defect site for Oxygen vacancy). Higher density of Nb substitutional defects (Nb sub ) are examined and it is shown that higher density doping of TiO 2 surface leads to uniform distribution of defects over the anatase structure as a result of interaction of Nb defects when they are close and this fact prevents segregation of Nb atoms in Nb-doped TiO 2 . |
| Databáze: | OpenAIRE |
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