<?xml version='1.0' encoding='utf-8'?> <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> <dc:creator>Poncé, Samuel</dc:creator> <dc:creator>Jia, Yongchao</dc:creator> <dc:creator>Giantomassi, Matteo</dc:creator> <dc:creator>Mikami, Masayoshi</dc:creator> <dc:creator>Gonze, Xavier</dc:creator> <dc:date>2021-08-20</dc:date> <dc:description>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.</dc:description> <dc:identifier>https://archive.materialscloud.org/record/2021.136</dc:identifier> <dc:identifier>doi:10.24435/materialscloud:sn-np</dc:identifier> <dc:identifier>mcid:2021.136</dc:identifier> <dc:identifier>oai:materialscloud.org:995</dc:identifier> <dc:language>en</dc:language> <dc:publisher>Materials Cloud</dc:publisher> <dc:rights>info:eu-repo/semantics/openAccess</dc:rights> <dc:rights>Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode</dc:rights> <dc:subject>first principles</dc:subject> <dc:subject>ab initio</dc:subject> <dc:subject>oxynitride phosphors</dc:subject> <dc:subject>thermal quenching</dc:subject> <dc:subject>photoluminescence</dc:subject> <dc:subject>BSON</dc:subject> <dc:subject>rare-earth</dc:subject> <dc:subject>FRS-FNRS</dc:subject> <dc:subject>CECI</dc:subject> <dc:title>Understanding thermal quenching of photoluminescence in oxynitride phosphors from first principles</dc:title> <dc:type>Dataset</dc:type> </oai_dc:dc>