摘要
Cyan-emitting Ca_(9)NaGd_(2/3)(PO_(4))_(7):Eu^(2+)phosphors were synthesized via high temperature solid-state route.X-ray powder diffraction(XRD)and scanning electron microscopy(SEM)were used to verify the phase and morphology of the Ca_(9)NaGd_(2/3)(PO_(4))_(7):Eu^(2+)(CNGP:Eu^(2+))phosphors.The as-obtained phosphor exhibits a broad excitation band of 250-420 nm,which is near the ultraviolet region.An intense asymmetric cyan emission at 496 nm corresponds to the 5 d-4 f transition of Eu^(2+).The multiplesite luminescent properties of Eu^(2+)ions in CNGP benefit from versatile structure ofβ-Ca3(PO4)2 compounds.The effective energy transfer distance is 5.46 nm(through the spectral overlap calculation),validating that the resonant energy migration type is via dipole-dipole interaction mechanism.Compared to the initial one at room temperature,the luminescent intensity of CNGP:Eu^(2+)phosphor can maintain 77%as it is heated up to 420 K.A white light-emitting diode(WLED)with excellent luminesce nt properties was successfully fabricated.Moreover,the CIE chromaticity coordinates of fabricated WLED driven by changing current just change slightly.
基金
Project supported by Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications(2019XGJSKFJJ01)
the Construction Program of the key discipline in Hunan Province
the Projects of the Education Department of Hunan Province(18A465)
Science and Technology Plan Project of Chenzhou City(jsyf2017014)
Natural Science Foundation of Shandong Province(ZR2018LB002)
Key Research and Development Project of Shandong Province(2019GGX102081)
Key Research and Development Project of Jining(2019ZDGH026)。
作者简介
Corresponding author:Bin Deng.College of Chemistry&Biology and Environmental Engineering,Xiangnan University,Chenzhou 423043,China,E-mail addresses:dengbinxnu@163.com;Corresponding author:Gongguo Zhang.E-mail addresses:zlwjxs@163.com.
