Transparent Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics containing BaF2nanocrystals are prepared.Under excitation of a 980-nm laser diode(LD),compared with the glass before heat treatment,the Tm3+/Er3+/Yb...Transparent Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics containing BaF2nanocrystals are prepared.Under excitation of a 980-nm laser diode(LD),compared with the glass before heat treatment,the Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics can emit intense blue,green and red up-conversion luminescence and Starksplit peaks;X-ray diffraction(XRD)and transmission electron microscope(TEM)results show that BaF2nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix.Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm3+,Er3+and(or)Yb3+ions are incorporated into the BaF2nanocrystals.The up-conversion luminescence intensities of Tm3+,Er3+and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension.In addition,the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed.展开更多
The Er3+/Yb3+co-doped transparent oxyfluoride glass-ceramics containing CaF2nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy(TEM) images showed that CaF2nano-crystals o...The Er3+/Yb3+co-doped transparent oxyfluoride glass-ceramics containing CaF2nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy(TEM) images showed that CaF2nano-crystals of 20–30 nm in diameter precipitated uniformly in the glass matrix. Comparing with the host glass, high efficiency upconversion luminescence of Er3+at 540 nm and 658 nm was observed in the glass ceramics under the excitation of 980 nm. Moreover,the size of the precipitated nano-crystals can be controlled by heat-treatment temperature and time. With the increase of the nano-crystal size, the intensity of the red emission increased more rapidly than that of the green emission. The energy transfer process of Er3+and Yb3+was convinced and the possible mechanism of Er3+up-conversion was discussed.展开更多
A novel red-emitting phosphor, CaYAl3O7 : Eu 3+ , Sm3+ , is synthesized by a combustion method at a low temperature (850℃), and the single phase of CaYAl3O7 is confirmed by powder X-ray diffraction measurements. The ...A novel red-emitting phosphor, CaYAl3O7 : Eu 3+ , Sm3+ , is synthesized by a combustion method at a low temperature (850℃), and the single phase of CaYAl3O7 is confirmed by powder X-ray diffraction measurements. The photoluminescence property results reveal that the red emission intensity of Eu3+ is strongly dependent on the Sm3+ concentration. Only the Eu 3+ luminescence is detected in the Eu 3+ -Sm3+ co-doped CaYAl3O7 phosphor with 393 nm excitation. However, under the characteristic excitation (402 nm) of Sm3+ , not only the Sm3+ emission but also the Eu 3+ emission are observed. A possible mechanism of the energy transfer between Sm3+ and Eu 3+ is investigated in detail.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61265004 and 51272097)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20125314120018)
文摘Transparent Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics containing BaF2nanocrystals are prepared.Under excitation of a 980-nm laser diode(LD),compared with the glass before heat treatment,the Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics can emit intense blue,green and red up-conversion luminescence and Starksplit peaks;X-ray diffraction(XRD)and transmission electron microscope(TEM)results show that BaF2nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix.Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm3+,Er3+and(or)Yb3+ions are incorporated into the BaF2nanocrystals.The up-conversion luminescence intensities of Tm3+,Er3+and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension.In addition,the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61265004,51272097,and 11204113)the Nature and Science Fund from Yunnan Province Ministry of Education,China(Grant No.2011C13211708)
文摘The Er3+/Yb3+co-doped transparent oxyfluoride glass-ceramics containing CaF2nano-crystals were successfully prepared. After heat treatments, transmission electron microscopy(TEM) images showed that CaF2nano-crystals of 20–30 nm in diameter precipitated uniformly in the glass matrix. Comparing with the host glass, high efficiency upconversion luminescence of Er3+at 540 nm and 658 nm was observed in the glass ceramics under the excitation of 980 nm. Moreover,the size of the precipitated nano-crystals can be controlled by heat-treatment temperature and time. With the increase of the nano-crystal size, the intensity of the red emission increased more rapidly than that of the green emission. The energy transfer process of Er3+and Yb3+was convinced and the possible mechanism of Er3+up-conversion was discussed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11204113, 61265004, and 51272097)the Foundation of Application Research of Yunnan Province, China (Grant No. 2011FB022)+2 种基金the Chinese Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20115314120001)the Postdoctoral Science Foundation of China (Grant No. 2011M501424)the National Basic Research Program of China (Grant No. 2011CB211708)
文摘A novel red-emitting phosphor, CaYAl3O7 : Eu 3+ , Sm3+ , is synthesized by a combustion method at a low temperature (850℃), and the single phase of CaYAl3O7 is confirmed by powder X-ray diffraction measurements. The photoluminescence property results reveal that the red emission intensity of Eu3+ is strongly dependent on the Sm3+ concentration. Only the Eu 3+ luminescence is detected in the Eu 3+ -Sm3+ co-doped CaYAl3O7 phosphor with 393 nm excitation. However, under the characteristic excitation (402 nm) of Sm3+ , not only the Sm3+ emission but also the Eu 3+ emission are observed. A possible mechanism of the energy transfer between Sm3+ and Eu 3+ is investigated in detail.
