Photoluminescence evolutions and physical mechanism discussions of Sr1.95-(Ca/Ba) MgSi2O7:Eu2+ phosphors
| Autor: | Ying-Ying Tu, Fa-Chun Lu, Zi-Han Yang, Chun-Hao Wang, Qing-Yang Wang, Xiang-Xiang Li, Ting-Wei Wang |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Photoluminescence Band gap Organic Chemistry Analytical chemistry Phosphor 02 engineering and technology Crystal structure 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics Spectral line 0104 chemical sciences Electronic Optical and Magnetic Materials Inorganic Chemistry Crystal Lattice constant Atomic electron transition Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology Spectroscopy |
| Zdroj: | Optical Materials. 110:110530 |
| ISSN: | 0925-3467 |
| Popis: | With Ca and Ba substitutions for Sr, the photoluminescence evolution of Sr2MgSi2O7:0.05Eu2+ has been investigated and discussed. With spectra and crystal structure analysis, the photoluminescence intensity variation, the emission band shift, the chromaticity coordinate evolution and the thermal stability changes have been revealed. The corresponding physical mechanisms have been discussed. With Ca/Ba substitution, the emission spectra show entire red/blue shift; while the photoluminescence intensity are both quenched. The crystal structure and lattice parameter variations were refined. Based on the reflection spectra measurements, the forbidden band gap of the series of Sr1.95-x(Ca/Ba)xMgSi2O7:0.05Eu2+ phosphors were calculated. Both for Ca and Ba substitution, the forbidden band gap is elevated. The regular emission band red/blue shifts are ascribed to the increased/decreased crystal splitting of the Eu2+ 5d electron. Based on the estimation of the crystal splitting intensity and the calculation of the forbidden band gap, the Eu2+ 5d electron transition process and the Ca/Ba substitution tuning process are illustrated. The thermal stability of Sr2MgSi2O7: Eu2+ is promoted with Ca/Ba substitution. The thermal quenching mechanism of this phosphor can be confirmed to self-ionization. This work proves cation substitution is a suitable route to tune the photoluminescence property of the phosphors. The revealed physical mechanisms are in favor of understanding the tuning process of the phosphors. |
| Databáze: | OpenAIRE |
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