Improved phase stability of the metastable K2GeF6:Mn4+ phosphors with high thermal stability and water-proof property by cation substitution

Tianchun Lang, Tao Han, Shuangqiang Fang, J. Wang, Shixiu Cao, Lingling Peng, B. Liu, Vladimir I. Korepanov, Aleksey N. Yakovlev

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)


K2GeF6:Mn4+ (KGFM) phosphors with very poor water-proof property in HF solution transform automatically from P63mc hexagonal phase to P3¯m1 trigonal phase. By substituting Ge4+ ion with Si4+ ion, the metastable P63mc hexagonal K2(Ge1-xSix)F6:Mn4+ (KGSFM) with an obvious zero-phonon line peaking at 623.8 nm is stabilized in HF solution. When x = 0.3, the photoluminescence intensity of KGSFM keeps 78% after 168 h in water as well as it increases by 14% at 150 °C (423 K) more than that of KGFM. By using KGSFM the fabricated WLEDs exhibit the high color-rendering index (Ra = 92) and low correlated color temperature (CCT = 3810 K). These results demonstrate that KGSFM solid solution with efficient red emission, meritorious water-proof and high thermal stability is a promising phosphor for the commercial application in the WLEDs and wide-gamut displays.

Original languageEnglish
Article number122429
JournalChemical Engineering Journal
Publication statusPublished - 15 Jan 2020


  • High thermal stability
  • KGeF:Mn
  • Metastable phase
  • Red phosphor
  • Water-proof

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

Fingerprint Dive into the research topics of 'Improved phase stability of the metastable K<sub>2</sub>GeF<sub>6</sub>:Mn<sup>4+</sup> phosphors with high thermal stability and water-proof property by cation substitution'. Together they form a unique fingerprint.

Cite this