Highly efficient non-rare-earth red emitting phosphor for warm white light-emitting diodes

• Published in: Nature communications Vol. 5; no. 1; p. 4312
• Main Authors: Zhu, Haomiao, Lin, Chun Che, Luo, Wenqin, Shu, Situan, Liu, Zhuguang, Liu, Yongsheng, Kong, Jintao, Ma, En, Cao, Yongge, Liu, Ru-Shi, Chen, Xueyuan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08-07-2014; Nature Publishing Group
• Subjects: 140/125; 639/301/1019/1020; 639/638/263; 639/638/439; 639/766/25; Champagne; Humanities and Social Sciences; Light emitting diodes; multidisciplinary; Optical properties; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms5312

Mn
4+
-activated fluoride compounds, as an alternative to commercial (oxy)nitride phosphors, are emerging as a new class of non-rare-earth red phosphors for high-efficacy warm white LEDs. Currently, it remains a challenge to synthesize these phosphors with high photoluminescence quantum yields through a convenient chemical route. Herein we propose a general but convenient strategy based on efficient cation exchange reaction, which had been originally regarded only effective in synthesizing nano-sized materials before, for the synthesis of Mn
4+
-activated fluoride microcrystals such as K
2
TiF
6
, K
2
SiF
6
, NaGdF
4
and NaYF
4
. Particularly we achieve a photoluminescence quantum yield as high as 98% for K
2
TiF
6
:Mn
4+
. By employing it as red phosphor, we fabricate a high-performance white LED with low correlated colour temperature (3,556 K), high-colour-rendering index (
R
a
=81) and luminous efficacy of 116 lm W
−1
. These findings show great promise of K
2
TiF
6
:Mn
4+
as a commercial red phosphor in warm white LEDs, and open up new avenues for the exploration of novel non-rare-earth red emitting phosphors.
Manganese-activated fluoride phosphors for high-efficacy warm white light-emitting diodes have been limited by low photoluminescence quantum yields. Here, Zhu
et al.
use an efficient cation exchange reaction to synthesize manganese phosphors with photoluminescence quantum yields as high as 98%.