Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cr...Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.展开更多
LuF_(3):yb^(3+),Er^(3+)microcrystals codoped with Yb^(3+)(rtyb^(3+)/nLu3+=5%-15%)and Er^(3+)ions(nEJnLu3+=1%-5%)were synthesized by a facile hydrothermal process at different pH values.It is found that the pH value ha...LuF_(3):yb^(3+),Er^(3+)microcrystals codoped with Yb^(3+)(rtyb^(3+)/nLu3+=5%-15%)and Er^(3+)ions(nEJnLu3+=1%-5%)were synthesized by a facile hydrothermal process at different pH values.It is found that the pH value has a crucial effect on synthesis of the orthorhombic phase LuF_(3):yb^(3+),Er^(3+).Under 980 nm excitation,LuF_(3):yb^(3+),Ephosphors exhibit strong green upconversion(UC)emission bands centered at 523(2H11/12→4I.15.2)and 539 nm(4S3.2→4I15/3)and weak red emissions near 660 nm(4F9a→4I15/2).The optimum doping concentrations of Er^(3+)and Yb^(3+)for the highest emission intensity were determined by using X-ray diffraction(XRD)and photoluminescence(PL)analyses.Concentration dependent studies reveal that the optimal composition is 10%Yb^(3+)and 2%Er^(3+)co-doping concen-tration with a strong green emission.A possible UC mechanism for LuFg:yb^(3+),Er^(3+)depends on the pump power is discussed.The temperature dependence of the fluorescence intensity ratios(FIR)for the two green UC emission bands peaked at 523 and 539 nm was studied in the range of 293-573 K under excitation by a 980 nm diode laser and the maximum sensitivity was approximately 15.3×10^(-4)K^(-1)at 490 K.This indicates that LuF_(3):Yb^(3+),Er^(3+)phosphors are potential candidates for optical temperature sensors with high sensitivity.展开更多
文摘Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.
文摘LuF_(3):yb^(3+),Er^(3+)microcrystals codoped with Yb^(3+)(rtyb^(3+)/nLu3+=5%-15%)and Er^(3+)ions(nEJnLu3+=1%-5%)were synthesized by a facile hydrothermal process at different pH values.It is found that the pH value has a crucial effect on synthesis of the orthorhombic phase LuF_(3):yb^(3+),Er^(3+).Under 980 nm excitation,LuF_(3):yb^(3+),Ephosphors exhibit strong green upconversion(UC)emission bands centered at 523(2H11/12→4I.15.2)and 539 nm(4S3.2→4I15/3)and weak red emissions near 660 nm(4F9a→4I15/2).The optimum doping concentrations of Er^(3+)and Yb^(3+)for the highest emission intensity were determined by using X-ray diffraction(XRD)and photoluminescence(PL)analyses.Concentration dependent studies reveal that the optimal composition is 10%Yb^(3+)and 2%Er^(3+)co-doping concen-tration with a strong green emission.A possible UC mechanism for LuFg:yb^(3+),Er^(3+)depends on the pump power is discussed.The temperature dependence of the fluorescence intensity ratios(FIR)for the two green UC emission bands peaked at 523 and 539 nm was studied in the range of 293-573 K under excitation by a 980 nm diode laser and the maximum sensitivity was approximately 15.3×10^(-4)K^(-1)at 490 K.This indicates that LuF_(3):Yb^(3+),Er^(3+)phosphors are potential candidates for optical temperature sensors with high sensitivity.
