Glass ceramics Ba2LaFT：xDy3＋ are obtained through the conventional melt-quenching technique, and their lu- minescent properties are investigated. Under 350 nm excitation, the emission spectra consists of a strong bl...Glass ceramics Ba2LaFT：xDy3＋ are obtained through the conventional melt-quenching technique, and their lu- minescent properties are investigated. Under 350 nm excitation, the emission spectra consists of a strong blue- yellow band as well as a weak red emission centered at 660 nm, which are attributed to the 4F9/2 →6H15/2, 4F9/2→6H13/2 and 4F9/2 → 6Hll/2 transitions of the Dy3＋ ion, respectively. The corresponding Commission Internationale de L＇Eclairage （CIE） chromaticity coordinate for a sample of 2 mol.% Dy203 after being heat-treated at 690℃ is （0.313, 0.328）. It is concluded that the formed materials may have the possibility of applications for white light-emitting diodes （LEDs）.展开更多
Ce^3＋/Tb^3＋ 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 im...Ce^3＋/Tb^3＋ 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 Ce^3＋ and Tb^3＋ 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 Ce^3＋ ions.Several characteristic sharp peaks centered at 489,543,578 and 620 nm originated from the ~5D4 to ~7FJ（J=6,5,4,3）of Tb^3＋ ions.The decay time of Tb^3＋ ions at 543 nm and the relevant energy levels of Ce^3＋ ions and Tb^3＋ ions illustrated the transfer process from Ce^3＋ ions to Tb^3＋ 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 YPO^4-based Ce^3＋/Tb^3＋ co-doped glass ceramics could act as potential luminescent materials for white light-emitting diodes.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61275180 and51472125)the K.C.Wong Magna Fund of Ningbo University
文摘Glass ceramics Ba2LaFT：xDy3＋ are obtained through the conventional melt-quenching technique, and their lu- minescent properties are investigated. Under 350 nm excitation, the emission spectra consists of a strong blue- yellow band as well as a weak red emission centered at 660 nm, which are attributed to the 4F9/2 →6H15/2, 4F9/2→6H13/2 and 4F9/2 → 6Hll/2 transitions of the Dy3＋ ion, respectively. The corresponding Commission Internationale de L＇Eclairage （CIE） chromaticity coordinate for a sample of 2 mol.% Dy203 after being heat-treated at 690℃ is （0.313, 0.328）. It is concluded that the formed materials may have the possibility of applications for white light-emitting diodes （LEDs）.
基金Project supported by the National Natural Science Foundation of China(6127518051472125)the K.C.Wong Magna Fund in Ningbo University
文摘Ce^3＋/Tb^3＋ 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 Ce^3＋ and Tb^3＋ 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 Ce^3＋ ions.Several characteristic sharp peaks centered at 489,543,578 and 620 nm originated from the ~5D4 to ~7FJ（J=6,5,4,3）of Tb^3＋ ions.The decay time of Tb^3＋ ions at 543 nm and the relevant energy levels of Ce^3＋ ions and Tb^3＋ ions illustrated the transfer process from Ce^3＋ ions to Tb^3＋ 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 YPO^4-based Ce^3＋/Tb^3＋ co-doped glass ceramics could act as potential luminescent materials for white light-emitting diodes.
