Blue-emitting K2Al2B2O7:Eu(2+) phosphor with high thermal stability and high color purity for near-UV-pumped white light-emitting diodes.
Novel blue-emitting K2Al2B2O7:Eu(2+) (KAB:Eu(2+)) phosphor was synthesized by solid state reaction. The crystal structural and photoluminescence (PL) properties of KAB:Eu(2+) phosphor, as well as its thermal properties of the photoluminescence, were investigated. The KAB:Eu(2+) phosphor exhibits broad excitation spectra ranging from 230 to 420 nm, and an intense asymmetric blue emission band centered at 450 nm under λex = 325 nm. Two different Eu(2+) emission centers in KAB:Eu(2+) phosphor were confirmed via their fluorescence decay lifetimes. The optimal concentration of Eu(2+) ions in K2-xEuxAl2B2O7 was determined to be x = 0.04 (2 mol %), and the corresponding concentration quenching mechanism was verified to be the electric dipole-dipole interactions. The PL intensity of the nonoptimized KAB:0.04Eu(2+) phosphor was measured to be ∼58% that of the commercial blue-emitting BaMgAl10O17:Eu(2+) phosphor, and this phosphor has high color purity with the CIE coordinate (0.147, 0.051). When heated up to 150 °C, the KAB:0.04Eu(2+) phosphor still has 82% of the initial PL intensity at room temperature, indicating its high thermal stability. These results suggest that the KAB:Eu(2+) is a promising candidate as a blue-emitting n-UV convertible phosphor for application in white light emitting diodes.
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.|‡University of Chinese Academy of Sciences, Beijing 100049, China.
Wenge
W
Xiao
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Xia
X
Zhang
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Zhendong
Z
Hao
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Guo-Hui
GH
Pan
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Yongshi
Y
Luo
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Ligong
L
Zhang
†State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Jiahua
J
Zhang