Optical properties of sonochemically synthesized rare earth ions doped BaTiO₃ nanophosphors: Probable candidate for white light emission

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• 作者：Dimple P. Dutta ; A. Ballal ; J. Nuwad ; A.K. Tyagi
• 关键词：Barium titanate ; Nanorods ; Transmission electron microscopy ; Photoluminescence ; Optically active materials ; CIE coordinates
• 刊名：Journal of Luminescence
• 出版年：April, 2014
• 年：2014
• 卷：148
• 期：Complete
• 页码：230-237
• 全文大小：1303 K

文摘

Undoped BaTiO₃ and doped BaTiO₃:RE (where RE=Sm³⁺, Ce³⁺, Dy³⁺, Tb³⁺and Eu³⁺) nanophosphors were synthesized sonochemically and characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDX (energy dispersive X-ray spectroscopy) and photoluminescence (PL) spectrophotometry. The resultant nanophosphors are single phase and rod shaped. The doped samples showed multicolor emission on single wavelength excitation. The luminescence decay curves for all the BaTiO₃:RE³⁺ (RE³⁺=Eu³⁺, Dy³⁺, Sm³⁺, Tb³⁺) samples fitted well into bi-exponential decay fit indicating availability of the dopant ions on surface and core regions of the sample. In case of the double doped BaTiO₃:Sm³⁺(2.5%):Tb³⁺(2.5%) sample, the green emission from Tb³⁺ was almost negligible. However, addition of Ce³⁺ ions in the Sm³⁺ and Tb³⁺ double doped host yielded relatively stronger green emission which has been assigned to energy-transfer between the Ce³⁺ and Tb³⁺ ions. The CIE coordinates of this triple doped BaTiO₃:Ce³⁺(2%): Tb³⁺(2%):Sm³⁺(1%) sample lie in the white light region of the chromaticity diagram and has a quantum efficiency of 58%. Thus, this sample shows promise as good phosphor material for new lighting devices.