Luminescent properties of Ce³⁺/Tb³⁺ co-doped glass ceramics containing YPO₄ nanocrystals for W-LEDs

张志雄，张约品，冯治刚，王成，夏海平，张新民

Key Laboratory of Photo-electronic Materials,Ningbo University

摘 要：Ce³⁺/Tb³⁺ co-doped transparent glass ceramics containing YPO₄ nanocrystals were prepared using high temperature melting method,and their structural and luminous properties were investigated.XRD analysis and TEM images confirmed the existence of YPO₄ nanocrystals in glass ceramics.The transmission spectra proved that the glass ceramics specimens still maintained a high transparency.Then the excitation and emission spectra of the Ce³⁺ and Tb³⁺ single-doped and co-doped glass and glass ceramics were discussed,which proved that the glass ceramics had better luminescent properties.Under the near ultraviolet（331 nm）excitation,the broadband emission located at 385 nm was observed which was ascribed to 5d→²F_5/2 and ²F_7/2 transition of Ce³⁺ ions.Several characteristic sharp peaks centered at 489,543,578 and 620 nm originated from the ⁵D₄ to ⁷F_J（J=6,5,4,3）of Tb³⁺ ions.The decay time of Tb³⁺ ions at 543 nm and the relevant energy levels of Ce³⁺ ions and Tb³⁺ ions illustrated the transfer process from Ce³⁺ ions to Tb³⁺ ions.The best CIE chromaticity coordinate of the glass ceramics specimen was calculated as（x=0.3201,y=0.3749）,which was close to the NTSC standard values for white（x=0.333,y=0.333）.All the results suggested that the YPO⁴-based Ce³⁺/Tb³⁺ co-doped glass ceramics could act as potential luminescent materials for white light-emitting diodes.

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