(Y0.87La0.1Zr0.03)2O3 nanopowders doped with various concentrations of Tm^3+ and Ho^3+ were prepared by the citrate method. The standard cubic Y2O3 phase can be matched in the Tm^3+/Ho^3+ co-doped(Y0.87La0.1Zr0...(Y0.87La0.1Zr0.03)2O3 nanopowders doped with various concentrations of Tm^3+ and Ho^3+ were prepared by the citrate method. The standard cubic Y2O3 phase can be matched in the Tm^3+/Ho^3+ co-doped(Y0.87La0.1Zr0.03)2 O3 nanopowders. The nanopowders exhibit average particle sizes of 40,60, 80 and 100 nm after calcinated at 900,1000,1100 and 1200℃,respectively. The energy transfer from Tm^3+ to Ho^3+ and the optimum fluorescence emission around 2 μm were investigated. Results indicate that the emission bands at around 1.86 and 1.95 μm correspond to 3 F4→3 H6 transition of Tm^3+ and 5 I7→5 I8 transition of Ho^3+, respectively.Better spectral properties were achieved in Tm^3+/Ho^3+ co-doped(Y0.87La0.1Zr0.03)2O3 nanopowders with the average size of 100 nm obtained at the conditions of the treatment of precursors calcinated at 1200 ℃ for 2 h doped with 1.5 mol% Tm^3+ and 1 mol% Ho^3+.展开更多
The effects of Li~+ co-doping concentration on the structure, upconversion luminescence and temperature sensing behavior of Er^(3+):La_2O_3 phosphors were investigated. X-ray diffraction and scanning electron mic...The effects of Li~+ co-doping concentration on the structure, upconversion luminescence and temperature sensing behavior of Er^(3+):La_2O_3 phosphors were investigated. X-ray diffraction and scanning electron microscopy observations reveal that Li~+ ion co-doping can change the lattice parameter of La_2O_3 host and increase the particle size of the samples. The optical investigation shows that co-doping of Li~+ ions can enhance the upconversion emission of Er^(3+) ions in La_2O_3 matrix effectively. Most importantly, the temperature sensing sensitivity of the samples is found to be dependent on Li~+ co-doping concentration,when the emission intensity ratio of the(~2H_(11/2)→~4 I_(15/2)) and(~4 S_(3/2)→~4 I_(15/2)) transitions of Er^(3+) is chosen as the thermometric index. Both of the optimum upconversion luminescence and temperature sensing sensitivity are obtained for 7 mol% Li~+ co-doped sample. When the Li~+ concentration is beyond 7 mol%,both the quenching in upconversion intensity and the degradation of temperature sensitivity are observed, which may be due to the serious distortion in local crystal field around Er^(3+) ions caused by the excess Li~+ ions.展开更多
Ho^3+/Yb^3+: BaMoO4 phosphors with different concentrations were fabricated by a gel combustion method.The upconversion(UC) luminescence, intrinsic optical bistability, and the corresponding mechanisms were reported f...Ho^3+/Yb^3+: BaMoO4 phosphors with different concentrations were fabricated by a gel combustion method.The upconversion(UC) luminescence, intrinsic optical bistability, and the corresponding mechanisms were reported for the present system. The optical thermometric properties based on red(^5F5→^5I8) and green(^5F4/^5S2→^5I8) emissions were studied. The sensing sensitivities could be tuned by manipulating the cooperative energy transfer process. The highest absolute sensitivity was 99 × 10^-4 K^-1 at 573 K, which is larger than that of many previous UC materials.展开更多
基金Project supported by Zhejiang Provincial Natural Science Foundation of China(LZ14B010001)
文摘(Y0.87La0.1Zr0.03)2O3 nanopowders doped with various concentrations of Tm^3+ and Ho^3+ were prepared by the citrate method. The standard cubic Y2O3 phase can be matched in the Tm^3+/Ho^3+ co-doped(Y0.87La0.1Zr0.03)2 O3 nanopowders. The nanopowders exhibit average particle sizes of 40,60, 80 and 100 nm after calcinated at 900,1000,1100 and 1200℃,respectively. The energy transfer from Tm^3+ to Ho^3+ and the optimum fluorescence emission around 2 μm were investigated. Results indicate that the emission bands at around 1.86 and 1.95 μm correspond to 3 F4→3 H6 transition of Tm^3+ and 5 I7→5 I8 transition of Ho^3+, respectively.Better spectral properties were achieved in Tm^3+/Ho^3+ co-doped(Y0.87La0.1Zr0.03)2O3 nanopowders with the average size of 100 nm obtained at the conditions of the treatment of precursors calcinated at 1200 ℃ for 2 h doped with 1.5 mol% Tm^3+ and 1 mol% Ho^3+.
基金Project supported by the National Natural Science Foundation of China(51401197,61605192)the Natural Science Foundation of Zhejiang Province(LQ13F050003,LZ14B010001)
文摘The effects of Li~+ co-doping concentration on the structure, upconversion luminescence and temperature sensing behavior of Er^(3+):La_2O_3 phosphors were investigated. X-ray diffraction and scanning electron microscopy observations reveal that Li~+ ion co-doping can change the lattice parameter of La_2O_3 host and increase the particle size of the samples. The optical investigation shows that co-doping of Li~+ ions can enhance the upconversion emission of Er^(3+) ions in La_2O_3 matrix effectively. Most importantly, the temperature sensing sensitivity of the samples is found to be dependent on Li~+ co-doping concentration,when the emission intensity ratio of the(~2H_(11/2)→~4 I_(15/2)) and(~4 S_(3/2)→~4 I_(15/2)) transitions of Er^(3+) is chosen as the thermometric index. Both of the optimum upconversion luminescence and temperature sensing sensitivity are obtained for 7 mol% Li~+ co-doped sample. When the Li~+ concentration is beyond 7 mol%,both the quenching in upconversion intensity and the degradation of temperature sensitivity are observed, which may be due to the serious distortion in local crystal field around Er^(3+) ions caused by the excess Li~+ ions.
基金supported by the Natural Science Foundation of Zhejiang Province(Nos.LY18E020008 and LD18F050001)the National Natural Science Foundation of China(No.61605192)
文摘Ho^3+/Yb^3+: BaMoO4 phosphors with different concentrations were fabricated by a gel combustion method.The upconversion(UC) luminescence, intrinsic optical bistability, and the corresponding mechanisms were reported for the present system. The optical thermometric properties based on red(^5F5→^5I8) and green(^5F4/^5S2→^5I8) emissions were studied. The sensing sensitivities could be tuned by manipulating the cooperative energy transfer process. The highest absolute sensitivity was 99 × 10^-4 K^-1 at 573 K, which is larger than that of many previous UC materials.