Enhanced quantum efficiency of a self-organized silica mixed red phosphor CaAlSiN3:Eu

Masatsugu Oishi, Shohei Shiomi, Koji Ohara, Fumito Fujishiro, Yoichiro Kai, Shao Ju Shih, Toshihiro Moriga, Shigefusa F. Chichibu, Aiko Takatori, Kazunobu Kojima

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


This study develops self-organized silica mixed CaAlSiN3:Eu (CASN) powder which improves light extraction efficiency (LEE) of the phosphor particles by enhanced scattering. A simple powder process conducted at room temperature, which is free from high temperature sintering process often applied for glass coated phosphors. Red phosphor CASN particles with a size of a few microns are mixed with nano-sized silica which was prepared in a tetraethyl orthosilicate (TEOS) solution of an alkali hydrolysis bath. The pair distribution function (PDF) profile obtained by an X-ray total scattering experiment indicates that the obtained nano-sized silica powders were amorphous. Compared to pure CASN powders, the composite CASN has an increased diffuse reflection, a reduced amount of absorption light, and an improved quantum efficiency (QE) of about 15%. QE is the product of internal quantum efficiency (IQE) and light extraction efficiency (LEE). The light emission lifetime measurement does not show a noticeable change between the pure and composite samples, indicating that the mixing process does not affect the electronic state of the Eu2+ luminescence center of CASN powder. That is, IQE of composite CASN is the same with that of pure CASN particles. Therefore, the improvement of QE of the composite CASN powders is due to the improvement of LEE.

Original languageEnglish
Article number122968
JournalJournal of Solid State Chemistry
Publication statusPublished - 2022 May


  • (Oxy)nitride phosphors
  • Amorphous silica mixture
  • Composites
  • Photoluminescence
  • Quantum efficiency

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry


Dive into the research topics of 'Enhanced quantum efficiency of a self-organized silica mixed red phosphor CaAlSiN3:Eu'. Together they form a unique fingerprint.

Cite this