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.

DOI https://doi.org/10.24435/materialscloud:sn-np
Source https://archive.materialscloud.org/record/2021.136
Metadata Access https://archive.materialscloud.org/xml?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai:materialscloud.org:995
Creator Poncé, Samuel; Jia, Yongchao; Giantomassi, Matteo; Mikami, Masayoshi; Gonze, Xavier
Publisher Materials Cloud
Publication Year 2021
Rights info:eu-repo/semantics/openAccess; Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode
OpenAccess true
Contact archive(at)materialscloud.org
Language English
Resource Type Dataset
Discipline Materials Science and Engineering