Synthesis, crystal structure and luminescence properties of a Y sub(4)Si sub(2)O sub(7)N sub(2):Ce super(3+) phosphor for near-UV white LEDs

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2014-06, Vol.2 (25), p.4967-4973
• Main Authors: Wu, Quansheng, Yang, Zhigang, Zhao, Zhengyan, Que, Meidan, Wang, Xicheng, Wang, Yuhua
• Format: Article
• Language: English
• Subjects: Conversion; Crystal structure; Emission; Lattice parameters; Luminescence; Phosphors; Polyhedrons; Wavelengths
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/c3tc32422b

A near-UV excited phosphor, Y sub(4)Si sub(2)O sub(7)N sub(2):Ce super(3+), was synthesized using a solid-state reaction. The crystal structure and luminescence properties were studied. Y sub(4)Si sub(2)O sub(7)N sub(2) crystallizes in a monoclinic unit cell with space group P2 sub(1)/c, lattice constants a= 7.5678(2) Aa, b= 10.4529(1) Aa, c= 10.7779(3) Aa and beta = 110.06 degree , and cell volume = 800.85(2) Aa super(3). The crystal structure of Y sub(4)Si sub(2)O sub(7)N sub(2), featuring Si(O,N) sub(4) polyhedra, is provided, and there are four different Y super(3+) coordination environments with two different coordination numbers in the structure. Ce super(3+)-doped Y sub(4)Si sub(2)O sub(7)N sub(2) exhibited a broad emission band, and the maximum emission wavelength could be tuned from blue ( lambda sub(em) = 450 nm) to green ( lambda sub(em) = 515 nm) by increasing the concentration of Ce super(3+). The quantum efficiency was determined to be about 47%. The results show that Y sub(4)Si sub(2)O sub(7)N sub(2):Ce super(3+) is a candidate for use as a conversion phosphor for near-UV white LED applications.