Automated Organization Profile

European Theoretical Spectroscopy Facility

Current S-Index

3.2

Sum of Dataset Indices for all datasets

Average Dataset Index per Dataset

1.6

Average Dataset Index per dataset

Total Datasets

2

Total datasets in this organization

Average FAIR Score

88.5%

Average FAIR Score per dataset

Total Citations

2

Total citations to the organization's datasets

Total Mentions

0

Total mentions of the organization's datasets

S-Index Interpretation

S-Index Over Time

Cumulative Citations Over Time

Cumulative Mentions Over Time

Datasets

Understanding thermal quenching of photoluminescence in oxynitride phosphors from first principles

Understanding the physical mechanisms behind thermal effects in phosphors is crucial for white light-emitting device (WLEDs) applications, as thermal quenching of their photoluminescence might render them useless. We analyze from first-principles, before and after absorption/emission of light, two chemically close Eu-doped Ba₃Si₆O₁₂N₂ and Ba₃Si₆O₉N₄ crystals for WLEDs. The first one has an almost constant emission intensity with increasing temperature whereas the other one does not. Our results, in which the Eu-5d levels are obtained inside the band gap thanks to the removal of an electron from the 4f⁷ shell, and the atomic neighborhood properly relaxed in the excited state, attributes the above-mentioned experimental difference to an autoionization model of the thermal quenching, based on the energy difference between Eu 5d and the conduction band minimum. Our depleted-shifted 4f method can identify luminescent centers and therefore allows for effective crystal site engineering of luminescent centers in phosphors from first principles.

Authors

  • Poncé, Samuel ;
  • Jia, Yongchao ;
  • Giantomassi, Matteo ;
  • Mikami, Masayoshi ;
  • Gonze, Xavier
1 Citation0 Mentions88% FAIR0.9 Dataset Index
10.24435/materialscloud:sn-np2021

Understanding thermal quenching of photoluminescence in oxynitride phosphors from first principles

Understanding the physical mechanisms behind thermal effects in phosphors is crucial for white light-emitting device (WLEDs) applications, as thermal quenching of their photoluminescence might render them useless. We analyze from first-principles, before and after absorption/emission of light, two chemically close Eu-doped Ba₃Si₆O₁₂N₂ and Ba₃Si₆O₉N₄ crystals for WLEDs. The first one has an almost constant emission intensity with increasing temperature whereas the other one does not. Our results, in which the Eu-5d levels are obtained inside the band gap thanks to the removal of an electron from the 4f⁷ shell, and the atomic neighborhood properly relaxed in the excited state, attributes the above-mentioned experimental difference to an autoionization model of the thermal quenching, based on the energy difference between Eu 5d and the conduction band minimum. Our depleted-shifted 4f method can identify luminescent centers and therefore allows for effective crystal site engineering of luminescent centers in phosphors from first principles.

Authors

  • Poncé, Samuel ;
  • Jia, Yongchao ;
  • Giantomassi, Matteo ;
  • Mikami, Masayoshi ;
  • Gonze, Xavier
1 Citation0 Mentions88% FAIR0.9 Dataset Index
10.24435/materialscloud:z9-jf2021