The effect of Er3＋ ion concentration on transient and steady-state behavior in 45-nm Er3＋ ：YAG crystal is investigated. It is shown that by changing the signal field, the coherent field and the concentration of Er3...The effect of Er3＋ ion concentration on transient and steady-state behavior in 45-nm Er3＋ ：YAG crystal is investigated. It is shown that by changing the signal field, the coherent field and the concentration of Er3＋ ions in the crystal, the absorption, dispersion, and group index of the weak probe field can be adjusted. Also, it is found that the probe absorption occurs in the presence of population inversion and probe amplification is obtained in the absence of population inversion.展开更多
Novel Er3+-doped bismuth lead strontiam glass was fabricated and characterized, and the absorption spectrum and upconversion spectrum of the glass were studied. The Judd-Ofelt intensity parameters Ωt (t=2, 4, 6) were...Novel Er3+-doped bismuth lead strontiam glass was fabricated and characterized, and the absorption spectrum and upconversion spectrum of the glass were studied. The Judd-Ofelt intensity parameters Ωt (t=2, 4, 6) were found to be Ω2=3.27×10-20 cm2, Ω4=1.15×10-20 cm2, and Ω6=0.38×10-20 cm2. The oscillator strength, the spontaneous transition probabilities, the fluorescence branching ratios, and excited state lifetimes were also measured and calculated. The upconversion emission intensity varies with the power of infrared excitation intensity. A plot of log Iup vs log IIR yields a straight line with slope 1.86, 1.88 and 1.85, corresponding to 525, 546, and 657 nm emission bands, respectively, which indicates that a two-photon process for the red and green emission.展开更多
Different concentrations of Mg^（2＋） -doped hexagonal phase NaGdF_4：Yb^（3＋）, Er^（3＋）nanocrystals（NCs） were synthesized by a modified solvothermal method. Successful codoping of Mg^（2＋）ions in upconversio...Different concentrations of Mg^（2＋） -doped hexagonal phase NaGdF_4：Yb^（3＋）, Er^（3＋）nanocrystals（NCs） were synthesized by a modified solvothermal method. Successful codoping of Mg^（2＋）ions in upconversion nanoparticles（UCNPs） was supported by XRD, SEM, EDS, and PL analyses. The effects of Mg^（2＋）doping on the morphology and the intensity of the upconversion（UC） emission were discussed in detail. It turned out that with the concentration of Mg^（2＋）increasing, the morphology of the nanoparticles turn to change gradually and the UC emission was increasing gradually as well. Notably the UC fluorescence intensities of Er^（3＋）were gradually improved owing to the codoped Mg^（2＋）and then achieved a maximum level as the concentration of Mg^（2＋）ions was 60 mol% from the amendment of the crystal structure of β-NaGdF_4：Yb^（3＋）,Er^（3＋）nanoparticles. Moreover, the UC luminescence properties of the rare-earth（Yb3＋, Er^（3＋）） ions codoped NaGdF_4 nanocrystals were investigated in detail under 980-nm excitation.展开更多
The EPR parameters of trivalent Er（3＋） ions doped in hexagonal Ga N crystal have been studied by diagonalizing the 364×364 complete energy matrices. The results indicate that the resonance ground states may be...The EPR parameters of trivalent Er（3＋） ions doped in hexagonal Ga N crystal have been studied by diagonalizing the 364×364 complete energy matrices. The results indicate that the resonance ground states may be derived from the Kramers doublet Γ6. The EPR g-factors may be ascribed to the stronger covalent bonding and nephelauxetic effects compared with other rare-earth doped complexes, as a result of the mismatch of ionic radii of the impurity Er（3＋）ion and the replaced Ga（3＋） ion apart from the intrinsic covalency of host Ga N. Furthermore, the J–J mixing effects on the EPR parameters from the high-lying manifolds have been evaluated. It is found that the dominant J–J mixing contribution is from the manifold 2K（15/2）, which accounts for about 2.5%. The next important J–J contribution arises from the crystal–field mixture between the ground state 4I（15/2） and the first excited state4I（13/2）, and is usually less than 0.2%. The contributions from the rest states may be ignored.展开更多
Er doped ZnO thin films were grown on Si substrates using SiO2 buffer layer by pulsed laser deposition (PLD) method. The obtained films crystallize well and show high c-axis orientation. The Er content was evidently d...Er doped ZnO thin films were grown on Si substrates using SiO2 buffer layer by pulsed laser deposition (PLD) method. The obtained films crystallize well and show high c-axis orientation. The Er content was evidently detected by the energy dispersive X-ray spectroscopy (EDS). Upon annealing in O2 ambience at different temperatures, the films show different photoluminescence properties at 1.54 μm. The samples annealed at 700 and 850 ℃ show intense photoluminescence peaks which enhance with the annealing temperature, while no obvious luminescence peaks are observed for the as-grown samples or annealed at 500 ℃. The possible mechanism was discussed.展开更多
文摘The effect of Er3＋ ion concentration on transient and steady-state behavior in 45-nm Er3＋ ：YAG crystal is investigated. It is shown that by changing the signal field, the coherent field and the concentration of Er3＋ ions in the crystal, the absorption, dispersion, and group index of the weak probe field can be adjusted. Also, it is found that the probe absorption occurs in the presence of population inversion and probe amplification is obtained in the absence of population inversion.
文摘Novel Er3+-doped bismuth lead strontiam glass was fabricated and characterized, and the absorption spectrum and upconversion spectrum of the glass were studied. The Judd-Ofelt intensity parameters Ωt (t=2, 4, 6) were found to be Ω2=3.27×10-20 cm2, Ω4=1.15×10-20 cm2, and Ω6=0.38×10-20 cm2. The oscillator strength, the spontaneous transition probabilities, the fluorescence branching ratios, and excited state lifetimes were also measured and calculated. The upconversion emission intensity varies with the power of infrared excitation intensity. A plot of log Iup vs log IIR yields a straight line with slope 1.86, 1.88 and 1.85, corresponding to 525, 546, and 657 nm emission bands, respectively, which indicates that a two-photon process for the red and green emission.
基金supported by the National High Technology Research and Development Program of China(Grant No.2013AA032205)the Key Project of Beijing Scientific Committee,China(Grant No.D161100003416001)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2016JBM066)the National Natural Science Foundation of China(Grant Nos.51272022 and 11474018)
文摘Different concentrations of Mg^（2＋） -doped hexagonal phase NaGdF_4：Yb^（3＋）, Er^（3＋）nanocrystals（NCs） were synthesized by a modified solvothermal method. Successful codoping of Mg^（2＋）ions in upconversion nanoparticles（UCNPs） was supported by XRD, SEM, EDS, and PL analyses. The effects of Mg^（2＋）doping on the morphology and the intensity of the upconversion（UC） emission were discussed in detail. It turned out that with the concentration of Mg^（2＋）increasing, the morphology of the nanoparticles turn to change gradually and the UC emission was increasing gradually as well. Notably the UC fluorescence intensities of Er^（3＋）were gradually improved owing to the codoped Mg^（2＋）and then achieved a maximum level as the concentration of Mg^（2＋）ions was 60 mol% from the amendment of the crystal structure of β-NaGdF_4：Yb^（3＋）,Er^（3＋）nanoparticles. Moreover, the UC luminescence properties of the rare-earth（Yb3＋, Er^（3＋）） ions codoped NaGdF_4 nanocrystals were investigated in detail under 980-nm excitation.
基金Project supported by the Foundation of Education Department of Shaanxi Province,China(Grant No.16JK1402)
文摘The EPR parameters of trivalent Er（3＋） ions doped in hexagonal Ga N crystal have been studied by diagonalizing the 364×364 complete energy matrices. The results indicate that the resonance ground states may be derived from the Kramers doublet Γ6. The EPR g-factors may be ascribed to the stronger covalent bonding and nephelauxetic effects compared with other rare-earth doped complexes, as a result of the mismatch of ionic radii of the impurity Er（3＋）ion and the replaced Ga（3＋） ion apart from the intrinsic covalency of host Ga N. Furthermore, the J–J mixing effects on the EPR parameters from the high-lying manifolds have been evaluated. It is found that the dominant J–J mixing contribution is from the manifold 2K（15/2）, which accounts for about 2.5%. The next important J–J contribution arises from the crystal–field mixture between the ground state 4I（15/2） and the first excited state4I（13/2）, and is usually less than 0.2%. The contributions from the rest states may be ignored.
基金This project was financially supported by the National Natural Science Foundation of China(No.50532060).
文摘Er doped ZnO thin films were grown on Si substrates using SiO2 buffer layer by pulsed laser deposition (PLD) method. The obtained films crystallize well and show high c-axis orientation. The Er content was evidently detected by the energy dispersive X-ray spectroscopy (EDS). Upon annealing in O2 ambience at different temperatures, the films show different photoluminescence properties at 1.54 μm. The samples annealed at 700 and 850 ℃ show intense photoluminescence peaks which enhance with the annealing temperature, while no obvious luminescence peaks are observed for the as-grown samples or annealed at 500 ℃. The possible mechanism was discussed.
