Jump to main content
Jump to site search

Issue 4, 2018
Previous Article Next Article

Composition-dependent thermal degradation of red-emitting (Ca1−xSrx)AlSiN3:Eu2+ phosphors for high color rendering white LEDs

Author affiliations

Abstract

Luminescence degradation under moisture and thermal attacks during the term of service cannot be ignored for phosphors used in solid state lighting. In this work, the moisture-assisted thermal degradation of two commercially available red phosphors (Ca1−xSrx)AlSiN3:Eu2+ with different Sr/Ca ratios (RP625: Sr/Ca = 0.9/0.1; RP660: Sr/Ca = 0/1) was investigated by treating phosphor powders at 170–230 °C for 8–96 h in pressurized water steam. The experimental results show that the chemical composition has a great impact on the thermal stability of (Ca1−xSrx)AlSiN3:Eu2+, and a lower Sr/Ca ratio results in a smaller thermal degradation. The activation energies for thermal degradation are 66.26 and 72.13 kJ mol−1 for RP625 and RP660, respectively. The phase transformation, microstructure evolutions, diffuse reflectance spectra, photoluminescence and cathodoluminescence spectra of samples before and after thermal treatment were discussed to reveal the thermal degradation mechanism. The serious degradation observed in RP625 is caused by the decomposition of the phosphor host and the oxidation of the Eu2+ dopant, which is closely related to the increased bond length of Sr/Ca/Eu–N chemical bonds.

Graphical abstract: Composition-dependent thermal degradation of red-emitting (Ca1−xSrx)AlSiN3:Eu2+ phosphors for high color rendering white LEDs

Back to tab navigation

Supplementary files

Publication details

The article was received on 24 Sep 2017, accepted on 18 Dec 2017 and first published on 19 Dec 2017


Article type: Paper
DOI: 10.1039/C7TC04356B
Citation: J. Mater. Chem. C, 2018,6, 890-898
  •   Request permissions

    Composition-dependent thermal degradation of red-emitting (Ca1−xSrx)AlSiN3:Eu2+ phosphors for high color rendering white LEDs

    F. Yao, L. Wang, Y. Lv, Y. Zhuang, T. Zhou and R. Xie, J. Mater. Chem. C, 2018, 6, 890
    DOI: 10.1039/C7TC04356B

Search articles by author

Spotlight

Advertisements