In recent years there has been growing interest in lanthanide-based multifunctional materials that exhibit interesting photophysical properties.This work presents spectroscopic and crystallographic characterization of...In recent years there has been growing interest in lanthanide-based multifunctional materials that exhibit interesting photophysical properties.This work presents spectroscopic and crystallographic characterization of a new dysprosium complex with sulfonylamidophosphate ligand.The crystal structure of[NaDy(SP)4]2·i-PrOH was determined and refined.It turns out that the Dy(Ⅲ)complex is not isostructural with earlier reported compounds and crystallizes in the monoclinic system(space group P21).Two crystallographically independent dysprosium atoms are in eight-fold coordination,with a triangular dodecahedron geometry.Absorption,emission(77 and 300 K)and excitation spectra as well as fluorescence decay time measurements allowed optical characterization of obtained complex.Efficient energy transfer from SP-ligand to Dy^3+ion has been demonstrated.The Judd-Ofelt theory was applied to predict fundamental fluorescence properties of Dy^3+ion in the title chelate.The Judd-Ofelt intensity parameters were used to determine the emission transition probabilities,fluorescence branching ratios and radiative lifetime of the emitting 4F9/2 level.The obtained results indicate that the investigated chelate can be a potential candidate for OLEDs emitting yellow light.展开更多
Tellurite glasses with the composition of xTm2O3-(6-x)Y2O3-3Na2O-25ZnO-66TeO2(where 0≤x≤6)were obtained by the melt-quenching technique.Absorption(300 K),excitation(300 K)and fluorescence spectra(300 K)as well as fl...Tellurite glasses with the composition of xTm2O3-(6-x)Y2O3-3Na2O-25ZnO-66TeO2(where 0≤x≤6)were obtained by the melt-quenching technique.Absorption(300 K),excitation(300 K)and fluorescence spectra(300 K)as well as fluorescence decay curves of Tm^3+-doped title glasses are presented and discussed in details.The Judd-Ofelt analysis based on the room temperature absorption spectrum was applied for determination of fundamental fluorescence properties such as radiative transition probabilities(AT),branching ratios(βR),radiative lifetimes(τR)of the emitting levels of the Tm^3+ion and stimulated emission cross-sections(σem).Fluorescence spectra were recorded and analysed in the visible and near-infrared spectral range.The emission and effective cross-section were calculated for the 3F4→3H6 transition,showing that the investigated glasses are promising laser host materials,operating at 1.8μm.The observed concentration quenching and non-exponential decay curves from the 1 G4 and 3H4 states indicate nonradiative energy transfer between Tm^3+ions.The analysis of non-exponential fluorescence decay curves from the 1 G4 and 3H4 levels was carried out in framework of the InokutiHirayama and Yokota-Tanimoto models and energy transfer microparameters were determined.The self-quenching model was proposed for describing relaxation of the first excited state of the Tm^3+ion.展开更多
文摘In recent years there has been growing interest in lanthanide-based multifunctional materials that exhibit interesting photophysical properties.This work presents spectroscopic and crystallographic characterization of a new dysprosium complex with sulfonylamidophosphate ligand.The crystal structure of[NaDy(SP)4]2·i-PrOH was determined and refined.It turns out that the Dy(Ⅲ)complex is not isostructural with earlier reported compounds and crystallizes in the monoclinic system(space group P21).Two crystallographically independent dysprosium atoms are in eight-fold coordination,with a triangular dodecahedron geometry.Absorption,emission(77 and 300 K)and excitation spectra as well as fluorescence decay time measurements allowed optical characterization of obtained complex.Efficient energy transfer from SP-ligand to Dy^3+ion has been demonstrated.The Judd-Ofelt theory was applied to predict fundamental fluorescence properties of Dy^3+ion in the title chelate.The Judd-Ofelt intensity parameters were used to determine the emission transition probabilities,fluorescence branching ratios and radiative lifetime of the emitting 4F9/2 level.The obtained results indicate that the investigated chelate can be a potential candidate for OLEDs emitting yellow light.
文摘Tellurite glasses with the composition of xTm2O3-(6-x)Y2O3-3Na2O-25ZnO-66TeO2(where 0≤x≤6)were obtained by the melt-quenching technique.Absorption(300 K),excitation(300 K)and fluorescence spectra(300 K)as well as fluorescence decay curves of Tm^3+-doped title glasses are presented and discussed in details.The Judd-Ofelt analysis based on the room temperature absorption spectrum was applied for determination of fundamental fluorescence properties such as radiative transition probabilities(AT),branching ratios(βR),radiative lifetimes(τR)of the emitting levels of the Tm^3+ion and stimulated emission cross-sections(σem).Fluorescence spectra were recorded and analysed in the visible and near-infrared spectral range.The emission and effective cross-section were calculated for the 3F4→3H6 transition,showing that the investigated glasses are promising laser host materials,operating at 1.8μm.The observed concentration quenching and non-exponential decay curves from the 1 G4 and 3H4 states indicate nonradiative energy transfer between Tm^3+ions.The analysis of non-exponential fluorescence decay curves from the 1 G4 and 3H4 levels was carried out in framework of the InokutiHirayama and Yokota-Tanimoto models and energy transfer microparameters were determined.The self-quenching model was proposed for describing relaxation of the first excited state of the Tm^3+ion.
