Study On Preparation,Spectral Modulation And Applications Of Rare-eath Ions Doped Borophosphate Fluorescent Glasses And Glass-ceramics

Rare-earth?RE?ions doped fluorescent materials have attracted much attention due to their wide technology applications in white light emitting diodes?W-LEDs?,display devices,lasers,solar cells and optical temperature sensors owing to their excellent luminescence properties.Fluorescent glass and glassceramics are considered as excellent host for RE ions because of compared with other optical materials they have incomparable advantages,such as transparent,homogeneous distinct visible emission,low cost and simpler manufacture procedure.Therefore,the research of RE ions doped fluorescent glasses and glass-ceramics has important scientific significance and applied value.In this paper,Eu³⁺,Tm³⁺,Tb³⁺ and Sm³⁺ ions single doped and co-doped Na2O-CaO-P2O5-B2O3-ZrO2 borophosphate glasses have been successfully synthesized via melt-quenching route,and Tb³⁺ and Eu³⁺ ions single doped and co-doped borophosphate glass-ceramics are prepared by controlled crtstallization method.The structural characteristic of borophosphate glasses and glassceramics are investigated by using X-ray powder diffraction,infrared spectroscopy,transmission electron microscopy?TEM?and density.The luminescence properties of borophosphate glass and glass-ceramics are characterized by absorption spectra,photoluminescence excitation?PLE?,photoluminescence?PL?spectra and chromaticity coordinates.Through fluorescent decay combined with relevant theory and formula studied the RE ions' energy transfer in RE ions co-doped borophosphate glasses and glass-ceramics.Furthermore,through the temperature-dependent emission spectra and use fluorescence intensity ratio confirmed the optical thermometry property of Tb³⁺/Eu³⁺ co-doped borophosphate glasses and glass-ceramics.The results of this study are lested as follow:1.Eu³⁺ single doped borophosphate glasses: XRD pattern exhibits that samples are all glasses and there is no any crystallization.The infrared spectra of glass samples shows that glasses were composed of [BO3],[BO4] and [PO4] basic structural units,and theses units are connected by P-O-P,P-O-B,B-O and P=O.Under 393 nm excitation,the emission spectra and fluorescent decay of glass samples indicated that the concentration quenching effect occurred when the concentration of Eu³⁺ increase to 2.5mol%.By calculating the chromaticity coordinates of Eu³⁺ single doped borophosphate glasses found that the chromaticity coordinates?0.65,0.34?close to the standard value for red?0.67,033?.2.Tb³⁺/Sm³⁺ co-doped borophosphate glasses: Under 374 nm excitation,the luminescent color of glass samples move in the yellow area,the color could be controled by varying the concentration of Sm³⁺ ions.The energy transfer process of Tb³⁺?Sm³⁺ in glass samples were confirmed by the emission spectra and fluorescent decay.The energy transfer process mainly cause by the resonance transfer of non-radiative relaxation,and the dominant mechanism of energy transfer process is electric quadrupole-quadrupole interaction.3.Tm³⁺/Tb³⁺/Sm³⁺ co-doped borophosphate glasses: Under 358 nm excitation,the luminescent color of galss samples enter into the white area which satisfies the basic chromaticity coordinate requirement of White-LED.With the concentration of Sm³⁺ increaing,the luminescent color of glasse samples tuned from cool white to warm white,the chromaticity coordinate?0.3339,0.3241?close to the standard white light?0.3333,0.3333?could be achieved in 0.4Tm³⁺/1.0Tb³⁺/0.8Sm³⁺?mol %?co-doped borophosphate glasses.The energy transfer process of Tm³⁺?Sm³⁺ and Tb³⁺?Sm³⁺in glass samples were confirmed by the emission spectra and fluorescent decay.The energy transfer process mainly cause by the resonance transfer of non-radiative relaxation.4.Tb³⁺/Eu³⁺ co-doped borophosphate glasses: Under 378 nm excitation,the luminescent color of galss samples moved in the yellow area,the color could be controled by varying the concentration of Eu³⁺ ions.The energy transfer process of Tb³⁺?Eu³⁺ in glass samples were confirmed by the emission spectra and fluorescent decay.The energy transfer process mainly cause by the resonance and cross relaxation transfer of non-radiative relaxation.The temperature-dependent?353-573K?emission spectra of glass sample shows that Tb³⁺/Eu³⁺ co-doped borophosphate glasses have an understanding property of optical thermometry,its absolute sensitivity is 0.0036K-1.5.Tb³⁺/Eu³⁺ co-doped borophosphate glassceramics: XRD pattern exhibits that the glassceramics contain NaCaPO4 crystal.According to the scherrer's equation and TEM analysis,the mean crystalline size is estimated to be about 13 nm.Under 378 nm excitation,the luminescent color of glassceramic samples moved in the yellow area,the color could be controled by varying the concentration of Eu³⁺ ions.The energy transfer process of Tb³⁺?Eu³⁺ in glassceramic samples were confirmed by the emission spectra and fluorescent decay.The energy transfer process mainly cause by the resonance and cross relaxation transfer of non-radiative relaxation.The temperature-dependent?293-573K?emission spectra of glassceramic sample shows that the optical thermometry property of Tb³⁺/Eu³⁺ co-doped borophosphate glassceramic is better than borophosphate glass.The absolute sensitivity and relative sensitivity of glassceramic sample is 0.0066K-1 and 4.55%K-1.