In this work,the Gd^(3+)/Eu^(3+) activated Ba_(3)Y_(4)O_(9)(BYO)phosphors were successfully synthesized via coprecipitation method at 1400℃.The precursor composition,crystal structure stability,microscopic morphology...In this work,the Gd^(3+)/Eu^(3+) activated Ba_(3)Y_(4)O_(9)(BYO)phosphors were successfully synthesized via coprecipitation method at 1400℃.The precursor composition,crystal structure stability,microscopic morphology,photoluminescence(PL)/photoluminescence excitation(PLE)spectra and fluorescence attenuation analysis of the phosphors are discussed in detail.The chemical composition of the precursor was determined by Fourier transform infrared spectroscopy(FT-IR)and thermogravimetry(TG)analysis;According to field emission-scanning electron microscopy(FE-SEM)analysis,it is found that the particle size of phosphor is uniform and the agglomeration is few.According to PL/PLE spectra analysis,Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors has the strongest excitation band at 260 nm and the strongest emission band at 614 nm,and the fluorescence intensity of Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) is higher than that of Ba_(3)Y^(3.4)Eu^(0.6)O_(9).The quenching concentration of Eu^(3+)in Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9) phosphors is x=0.15 and the mechanism of quenching concentration of Eu^(3+)is electric dipole-quadrupole type interactions.The lifetime value of Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9)(x=0.15)phosphors is 0.686 ms and decreases with the increase of Eu^(3+)content.In addition,the CIE chromaticity diagram of Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors is(0.66,0.34).Finally,the lamp beads assembled with Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors have an ideal luminous effect.Therefore,the Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9) phosphors designed in this work may hopefully meet the requirements of various lighting and optical display applications.展开更多
A periodically poled lithium niobate （PPLN） optical parametric generator （OPG） pumped by a laser diode （LD）-pumped Q-switched Tm,Ho：GdVO4 laser operated at 2.048 μm with pump pulse of 25 ns and repetition rate...A periodically poled lithium niobate （PPLN） optical parametric generator （OPG） pumped by a laser diode （LD）-pumped Q-switched Tm,Ho：GdVO4 laser operated at 2.048 μm with pump pulse of 25 ns and repetition rate of 10 kHz is reported. A continuous tunable middle-infrared （mid-IR） spectrum of 3.88 - 4.34 μm is obtained by changing the crystal temperature from 50 to 124℃. When the incident pump power is 3 W, the total OPG output power is 95 mW, corresponding to optical conversion efficiency of 3.2%.展开更多
基金Project supported by the National Natural Science Foundation of China (51402125)China Postdoctoral Science Foundation (2017M612175)+1 种基金Special Fund of Postdoctoral Innovation Project in Shandong Province (201603061)Natural Science Foundation of Shandong Province (ZR2020ME045,ZR2020ME046)。
文摘In this work,the Gd^(3+)/Eu^(3+) activated Ba_(3)Y_(4)O_(9)(BYO)phosphors were successfully synthesized via coprecipitation method at 1400℃.The precursor composition,crystal structure stability,microscopic morphology,photoluminescence(PL)/photoluminescence excitation(PLE)spectra and fluorescence attenuation analysis of the phosphors are discussed in detail.The chemical composition of the precursor was determined by Fourier transform infrared spectroscopy(FT-IR)and thermogravimetry(TG)analysis;According to field emission-scanning electron microscopy(FE-SEM)analysis,it is found that the particle size of phosphor is uniform and the agglomeration is few.According to PL/PLE spectra analysis,Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors has the strongest excitation band at 260 nm and the strongest emission band at 614 nm,and the fluorescence intensity of Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) is higher than that of Ba_(3)Y^(3.4)Eu^(0.6)O_(9).The quenching concentration of Eu^(3+)in Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9) phosphors is x=0.15 and the mechanism of quenching concentration of Eu^(3+)is electric dipole-quadrupole type interactions.The lifetime value of Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9)(x=0.15)phosphors is 0.686 ms and decreases with the increase of Eu^(3+)content.In addition,the CIE chromaticity diagram of Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors is(0.66,0.34).Finally,the lamp beads assembled with Ba_(3)Y_(3.28)Eu_(0.6)Gd_(0.12)O_(9) phosphors have an ideal luminous effect.Therefore,the Ba_(3)Y_(3.88–4x)Eu_(4x)Gd_(0.12)O_(9) phosphors designed in this work may hopefully meet the requirements of various lighting and optical display applications.
基金the Scientific Research Foundation of Harbin Institute of Technology.
文摘A periodically poled lithium niobate （PPLN） optical parametric generator （OPG） pumped by a laser diode （LD）-pumped Q-switched Tm,Ho：GdVO4 laser operated at 2.048 μm with pump pulse of 25 ns and repetition rate of 10 kHz is reported. A continuous tunable middle-infrared （mid-IR） spectrum of 3.88 - 4.34 μm is obtained by changing the crystal temperature from 50 to 124℃. When the incident pump power is 3 W, the total OPG output power is 95 mW, corresponding to optical conversion efficiency of 3.2%.
