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Preparation and luminescence properties of β-SiAlON:Eu2+ green phosphor for high color gamut
|Youn-Gon Park , Jeong Ho Ryu , Chul Soo Yoon|
Samsung Electro Mechanics Co, 314, Meatan 3-Dong, Suwon 443-743, Korea, South
The structure of β-SiAlON is derived from β-Si3N4 by equivalent substitution of Al-O for Si-N, and its chemical composition can be written as Si6-zAlzOzN8-z (z represents the number of Al-O pairs substituting for Si-N pairs and 0 ＜ z ≤ 4.2). β-SiAlON has a hexagonal crystal structure and the P63 space group. In this structure there are continuous channels parallel to the c direction. During the last few decades SiAlON ceramics have drawn much attention since they can be sintered to full density with with low amounts of glassy phase, resulting in good mechanical properties even at high temperature. Recently optical properties have also been studied. It was observed that SiAlONs doped with 3d or 4f transition elements can be used as pigments or as luminescent materials. The luminescence wavelength of an ion in a matrix is strongly influenced by the anion neighbors of the ion.
A green-emitting oxynitride phosphor powder β-SiAlON:Eu2+ with composition of Eu0.013Si5.769Al0.231O0.205N7.795 was prepared from aEuO-bSi3N4-cAlN system using a by gas pressure sintering method. The powder mixture was synthesized at 1900 ℃ for 2 hrs in 0.9 MPa N2 atmosphere. The prepared phosphor powder exhibits a hexagonally shaped morphology with the length of ≈ 4㎛ and the diameter of ≈ 0.5㎛. The crystallinity, surface morphology and chemical composition were presented. And moreover, not only photoluminescence (PL) properties were investigated but also quantum efficiencies and absorption were made an inventory of prepared β-SiAlON:Eu2+ phosphor powders in a wavelength range from 300 to 600 nm. It can be exited efficiently over a broad spectral range between 255 and 520 nm, and has an emission peak at 540 nm with a full width at half maximum below 55 nm. It has a superior color chromaticity of x = 0.32 and y = 0.64. The internal and external quantum efficiencies of phosphor is 64 % and 52 % at λex = 303nm, respectively.
Presentation: Oral at E-MRS Fall Meeting 2007, Symposium A, by Youn-Gon Park
See On-line Journal of E-MRS Fall Meeting 2007
Submitted: 2007-05-14 07:28 Revised: 2009-06-07 00:44