# Fileset

[A.Nakanishi 34thMRS-J abst.pdf](https://mdr.nims.go.jp/filesets/d221d1ef-1a8e-4602-9578-f87aef8e39a9/download)

## Creator

[中西 昭博](https://orcid.org/0009-0001-1859-261X), [小山 幸典](https://orcid.org/0000-0002-7090-4430), [中西 貴之](https://orcid.org/0000-0003-3412-2842), [高橋 向星](https://orcid.org/0000-0002-6443-1534), [廣崎 尚登](https://orcid.org/0000-0001-9218-9557), 池野豪一, [武田 隆史](https://orcid.org/0000-0003-2510-4562)

## Rights

[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Characterization of narrow-band emitting phosphor Na5Al3F14:Eu2+ discovered by local  structure similarity ](https://mdr.nims.go.jp/datasets/055b0d11-080c-45c5-ba73-cd8d75de972e)

## Fulltext

34thMRS-J   Characterization of narrow-band emitting phosphor Na5Al3F14:Eu2+ discovered by local structure similarity *A. Nakanishi1), Y. Koyama1), T. Nakanishi1), K. Takahashi1), N. Hirosaki1), H. Ikeno2), and T. Takeda1) 1)National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan  2)Department of Materials Science, Graduate School of Engineering, Osaka Metropolitan University, Sakai, Osaka 599-8570, Japan * NAKANISHI.Akihiro@nims.go.jp Phosphor-converted light-emitting diodes (pc-LEDs) have applications in various fields, taking advantages of their high energy efficiency and long lifetime. The emission color of the phosphor is derived from the luminescence spectrum, especially the excitation, emission wavelength, and the full width at half maximum (FWHM). Narrow-band emitting phosphors are utilized for the backlight of liquid crystal displays (LCDs) to improve the color purity of red-green-blue light and expand the color gamut of display. The nitride phosphor SrLiAl3N4:Eu2+ with the UCr4C4-type structure has attracted much attention because it has the narrow-band red emission [1]. However, the discovery of the narrow-band emitting phosphors is a challenging program because the relationship between the full width at half maximum (FWHM) and the local structure around Eu2+ is still unknown.  Data-driven approach is an effective technique to search the host material of the narrow-band emitting phosphors. Herein, we discovered a new narrow-band emitting phosphor Na5Al3F14:Eu2+ by a local structure similarity (LSS) [2]. 2D t-distributed stochastic neighbor embedding (t-SNE) plot for the 8-coordinated local structures are shown in Fig. 1. This plot revealed that the local structure of Na1-site of the Na5Al3F14 located to near the Sr-sites of the narrow-band emitting phosphor SrLiAl3N4:Eu2+, indicating that the Na5Al3F14 is a suitable host material for the Eu2+-activated narrow-band emitting phosphor. We successfully synthesized a powder of the narrow-band emitting phosphor Na5Al3F14:Eu2+ by a solid-state reaction method. Na5Al3F14:Eu2+ exhibited a narrow-band emission at 396 nm with a full width at half-maximum of 30 nm. References: [1] P. Pust et al., Nature Mater. 13 (2014) 891-896, [2] S. Takemura et al., Sci. Technol. Adv. Mater. 22 (2021) 185-193.  Fig. 1. 2D t-SNE plot for 8-coordinated alkali-centered local structure. mailto:NAKANISHI.Akihiro@nims.go.jp