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: England Nature Publishing Group 08.07.2014
• Subjects: Champagne; Light emitting diodes; Optical properties
• 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 K2TiF6, K2SiF6, NaGdF4 and NaYF4. Particularly we achieve a photoluminescence quantum yield as high as 98% for K2TiF6: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 (Ra=81) and luminous efficacy of 116 lm W(-1). These findings show great promise of K2TiF6: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.