Revealing The Degradation Mechanism of (Sr,Ca)AlSiN₃:Eu²⁺ Phosphor Aged Under Thermal-Moisture-Sulfur Conditions

Revealing The Degradation Mechanism of (Sr,Ca)AlSiN₃:Eu²⁺ Phosphor Aged Under Thermal-Moisture-Sulfur Conditions: A Combined Experimental and Ab Initio Study

Guo, Baotong (Fudan University)
Wen, Minzhen (Fudan University)
Tang, Hongyu (Fudan University)
Lishik, Sergey (Center of LED and Optoelectronic Technologies of NAS Belarus)
Fan, X. (TU Delft Electronic Components, Technology and Materials; Lamar University College of Engineering)
Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)
Fan, J. (TU Delft Electronic Components, Technology and Materials; Fudan University; Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences; Fudan Zhangjiang Institute)

2024

MAlSiN₃:Eu²⁺ (M = Ca, Sr) is commonly used in high-power phosphor-converted white-light-emitting diodes and laser diodes to promote their color-rendering index. However, the wide application of this phosphor is limited by the degradation of its luminescent properties in high-temperature, high-humidity, and high-sulfur-content environment. Here, the degradation mechanism of the (Sr,Ca)AlSiN₃:Eu²⁺ (SCASN) red phosphor under thermal-moisture-sulfur coupling conditions is investigated. Furthermore, by performing first-principles calculations, the hydrolysis mechanism on an atomic scale is assessed. The adsorption energy (E_ads) and charge transfer (ΔQ) results showed that H₂O chemically adsorbed on the (0 1 0), (3 1 0), and (0 0 1) surfaces of the CaAlSiN₃ (CASN) host lattice. The energy barrier for H₂O dissociation is only 29.73 kJ mol⁻¹ on the CASN (0 1 0) surface, indicating a high dissociation probability. The formation of NH₃, Ca(OH)₂, and CaAl₂Si₂O₈ is confirmed by H⁺ tended to combine with surface N atoms, while OH⁻ combined with the surface Al/Si or Ca atoms. Moreover, ab initio molecular dynamics simulations were performed to further understand the hydrolysis process. This work offers a guidance on the design and applications of luminescent materials in LED packages with higher reliability and stability requirements in harsh environment.

(Sr
Ca)AlSiN:Eu phosphor
degradation mechanism
first-principles calculation
hydrolysis reaction
sulfur and hydrogen sulfide

http://resolver.tudelft.nl/uuid:cf5921b2-6655-41c6-a88e-173e0ac3c93b

https://doi.org/10.1002/lpor.202300838

2024-07-31

1863-8880

Laser and Photonics Reviews, 18 (4)

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2024 Baotong Guo, Minzhen Wen, Hongyu Tang, Sergey Lishik, X. Fan, Kouchi Zhang, J. Fan