In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I1...In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I15/2 emission were measured. The Er-concentration dependence of integrated intensity and lifetime of ^4I13/2→^4I15/2 emission are showed. With the increase of the Er^3＋ doping concentration, the 1.5 μm fluorescence emission first increases, then decreases, and the lifetime falls gradually. With 980 nm excitation, the efficiency of the energy transfer from Er^3＋ to quenching centers reaches 73.73% for the sample with 4 mol% Er^3＋. Meanwhile, owing to the relation of fluorescence integrated intensity and Er-concentration, a dipole-dipole quenching mechanism in the framework of a limited diffusion regime has been proved. Using the limited diffusion case, the critical concentration for quenching has been determined from a fitting equation of the lifetime and Er-concentration. The fit- ting result shows the critical concentration for quenching is higher than the values obtained in Er-doped different glass by an order of magnitude.展开更多
Pr3+and Yb3+co-doped phosphate glasses are prepared to study their optical properties.Excitation and emission spectra and decay curves are used to characterize their luminescence.We demonstrate that upon excitation of...Pr3+and Yb3+co-doped phosphate glasses are prepared to study their optical properties.Excitation and emission spectra and decay curves are used to characterize their luminescence.We demonstrate that upon excitation of Pr3+ion with one high energy photon at 470 nm,two near-infrared(NIR)photons are emitted at 950-1100 nm(Yb3+:2F 5/2 →2F 7/2)through an efficient cooperative energy transfer(CET)from Pr3+to Yb3+.The maximum energy transfer efficiency(ETE)and the corresponding quantum efficiency approach up to 90.17%and 190.17%,respectively.The glass materials might find potential application for improving the efficiency of silicon-based solar cells.展开更多
基金supported by the Fujian Natural Science Foundation of China (Grant No. 2009J05139)the Fujian Science and Technology major projects of China (Grant No. 2007HJ0004-2)+1 种基金the Project of Education Department of Fujian Province of China (Grant No. JK2011008)the Innovation Project for Young Scientists of Fujian Province of China (Grant No. 2007F3027)
文摘In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I15/2 emission were measured. The Er-concentration dependence of integrated intensity and lifetime of ^4I13/2→^4I15/2 emission are showed. With the increase of the Er^3＋ doping concentration, the 1.5 μm fluorescence emission first increases, then decreases, and the lifetime falls gradually. With 980 nm excitation, the efficiency of the energy transfer from Er^3＋ to quenching centers reaches 73.73% for the sample with 4 mol% Er^3＋. Meanwhile, owing to the relation of fluorescence integrated intensity and Er-concentration, a dipole-dipole quenching mechanism in the framework of a limited diffusion regime has been proved. Using the limited diffusion case, the critical concentration for quenching has been determined from a fitting equation of the lifetime and Er-concentration. The fit- ting result shows the critical concentration for quenching is higher than the values obtained in Er-doped different glass by an order of magnitude.
基金supported by the National Natural Science Foundation of China(Nos.61275180,51272109and50972061)the Natural Science Foundation of Zhejiang Province(Nos.Z4110072and R4100364)+1 种基金the Opening Foundation of Zhejiang Provincial Top Key DisciplineK.C.Wong Magna Fund in Ningbo University
文摘Pr3+and Yb3+co-doped phosphate glasses are prepared to study their optical properties.Excitation and emission spectra and decay curves are used to characterize their luminescence.We demonstrate that upon excitation of Pr3+ion with one high energy photon at 470 nm,two near-infrared(NIR)photons are emitted at 950-1100 nm(Yb3+:2F 5/2 →2F 7/2)through an efficient cooperative energy transfer(CET)from Pr3+to Yb3+.The maximum energy transfer efficiency(ETE)and the corresponding quantum efficiency approach up to 90.17%and 190.17%,respectively.The glass materials might find potential application for improving the efficiency of silicon-based solar cells.
