Crystal-Site Engineering of Novel Na3KMg7(PO4)6–x (BO3) x :Eu2+ Phosphors for Full-Spectrum Lighting

• Published in: Inorganic chemistry 2024-04, Vol.63 (17), p.7984-7991
• Main Authors: You, Fengluan, Wang, Shaoxiong, Pang, Tao, Wu, Tianmin, Lin, Bing, Zeng, Lingwei, Lin, Shisheng, Yang, Luan, Fang, Yongzheng, Chen, Daqin
• Format: Article
• Language: English
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.4c01113

The “cyan gap” is the bottleneck problem in violet-driven full-spectrum white-light-emitting diodes (wLEDs) in healthy lighting. Accordingly, we develop a novel broadband-blue-cyan emission Na3KMg7(PO4)6–x (BO3) x :Eu2+ (NKMPB:Eu2+) phosphor via crystal-site engineering. This phosphor is derived from the Na3KMg7(PO4)6:Eu2+ phosphor, which shows desired abundant cyan emissive components. A comparative study is conducted to reveal the microstructure–property relationship and the key influential factors to its spectrum distribution. It can be found that the introduced (BO3)3– units can manipulate the site-selective occupation of Eu2+ activators, asymmetrically broadening the emission spectrum in NKMPB:Eu2+. Considering detailed luminescence performance analysis and the density functional theory calculations, a new substitution pathway of Eu2+ is created by substituting (PO4)3– with (BO3)3– units, making partial Eu2+ ions enter the Mg2+ (CN = 5, CN = 6) crystallographic sites, and yielding an extra emission band at 600 nm (16667 cm–1) and especially 501 nm (19960 cm–1). Meanwhile, a high-color-quality full-spectrum-emitting wLEDs was fabricated, upon 100 mA forward-bias current driven. Due to the achieved extra cyan emissive components of NKMPB:Eu2+, the constructed NKMPB:Eu2+-based wLEDs show better color rendering ability (∼90.9) than that of Na3KMg7(PO4)6:Eu2+-based wLEDs (∼86.3), and also demonstrate its great potential in full-spectrum healthy lighting.