DFT Calculation of Rhodium-Doped Silver Bromide Crystals: Defect Structures, Photoelectric Property and EPR
| Autor: | Shao-Yi Wu, Li-Juan Zhang, Gao-Jun Zhang, Li-Na Wu, Xu-Sheng Liu |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Doping General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Photoelectric effect 010402 general chemistry 021001 nanoscience & nanotechnology Silver bromide 01 natural sciences 0104 chemical sciences law.invention Rhodium chemistry.chemical_compound Ultraviolet visible spectroscopy chemistry law Physical chemistry Physical and Theoretical Chemistry 0210 nano-technology Electron paramagnetic resonance Mathematical Physics |
| Zdroj: | Zeitschrift für Naturforschung A. 74:59-69 |
| ISSN: | 1865-7109 0932-0784 |
| DOI: | 10.1515/zna-2018-0327 |
| Popis: | AgBr crystals containing impurity Rh2+ with and without a next nearest neighbor silver vacancy (VAg) in the [001] axis are theoretically studied. The defect structures, bandgap, Mulliken charge, density of states, ultraviolet-visible (UV-Vis) and electron paramagnetic resonance spectra are analysed for two distinct (i.e. tetragonally elongated and compressed) centres by using density functional theory calculations. The results demonstrate that the structural, photoelectric and spectroscopic properties of AgBr are significantly changed after Rh substitution. The covalency of Rh-Br bonds in the two centres is stronger than that of pure AgBr according to the larger magnitudes of the overlap population. Compared to pure AgBr, Rh doping also results in significantly enhanced red shifts of absorption bands in the UV-Vis region and some new d-d transitions in the visible and near-infrared regions. Meanwhile, the bandgap of Rh-doped AgBr is about 10 % narrower than that of pure AgBr. As a result, the visible light activity may be enhanced in AgBr:Rh systems. Rh dopants can induce the magnetic moments of about 1.73 μB for both centres. Therefore, transition-metal Rh dopants may effectively modulate the electronic, optical and magnetic properties of AgBr. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|