Optical thermometry as an important local temperature-sensing technique,has received increasing attention in scientific and industrial areas.However,it is still a big challenge to develop luminescent materials with se...Optical thermometry as an important local temperature-sensing technique,has received increasing attention in scientific and industrial areas.However,it is still a big challenge to develop luminescent materials with self-activated dual-wavelength emissions toward high-sensitivity optical thermometers.Herein,a novel ratiometric thermometric strategy of Bi^(3+)-activated dual-wavelength emission band was realized in the same lattice position with two local electronic states of La_(3)Sb_(1-x)Ta_xO_(7):Bi^(3+)(0≤x≤1.0)materials based on the different temperature-dependent emission behaviors,benefiting from the highlysensitive and regulable emission to the coordination environment of Bi^(3+).The structural and spectral results demonstrate that the emission tremendously shifted from green to blue with 68 nm and the intensity was enhanced 2.6 times.Especially,the visual dual-wavelength emitting from two emission centers was presented by increasing the Ta^(5+)substitution concentration to 20%or 25%,mainly originating from the two local electronic states around the Bi^(3+)emission center.Significantly,the dual-wavelength with different thermal-quenching performance provided high-temperature sensitivity and good discrimination signals for optical thermometry in the range between 303 and 493 K.The maximum relative sensitivity reached 2.64%/K(La_(3)Sb_(0.8)Ta_(0.2)O_(7):0.04Bi^(3+)@383 K)and 1.91%/K(La_(3)Sb_(0.75)Ta_(0.25)O_(7):0.04Bi^(3+)@388 K).This work reveals a rational design strategy of different local electronic states around the singledoping multiple emission centers towards practical applications,such as luminescence thermometry and white LED lighting.展开更多
In order to meet the needs of new materials gradually developing towards miniaturization,integration,and light weight,multifunctional BaNb_(2)O_(6):Yb^(3+)/Er^(3+)/Tm^(3+)transparent glass-ceramics were success-fully ...In order to meet the needs of new materials gradually developing towards miniaturization,integration,and light weight,multifunctional BaNb_(2)O_(6):Yb^(3+)/Er^(3+)/Tm^(3+)transparent glass-ceramics were success-fully prepared by melt quenching and controllable crystallization.Its structure,luminescence,and en-ergy transmission were studied.Using the opposite temperature dependence of the Tm^(3+)emission band and the corresponding large energy level gap,a maximum relative sensitivity of 2.3%K^(-1)based on thermal coupling levels(TCLs)is obtained in a wide temperature range(298-673 K).The multi-ratio optical thermometry based on TCLs and non-TCLs is successfully realized by using the different emission bands of double emission centers,which makes it possible for self-reference optical temperature measurement modes.In addition,the transparent glass-ceramic exhibits excellent electrical properties under 700 kV cm^(-1)electric field:high discharge energy density(W_(d)=0.99 J cm^(-3)),huge instantaneous power density(225.3 MW cm^(-3)),and ultra-fast discharge rate(T_(0.9)≤15.8 ns).The prepared glass-ceramic is expected to be a new type of lead-free multifunctional photoelectric material for temperature sensors and transparent electronic devices.展开更多
A novel non-contact optical thermometer,qualified with high sensitivity and temperature resolution,is urgently needed for temperature measuring of micro devices,moving objects and specific severe environments.Hence,a ...A novel non-contact optical thermometer,qualified with high sensitivity and temperature resolution,is urgently needed for temperature measuring of micro devices,moving objects and specific severe environments.Hence,a series of dual-emitting La_(5)Si_(2)BO_(13):Ce^(3+),Eu^(2+)phosphors were synthesized.The two ions show diverse responses with the changing in temperature.The variational emissions of Ce^(3+)and Eu^(2+)can be converted to FIR(fluorescence intensity ratio)signals.The maximal absolute sensitivity Sa and relative sensitivity Sr reach up to 0.07526%/K and 3.2241%/K,respectively.It is worthy noting that the Sa and Sr possess the same variation tendency and both have high values in the low temperature region(293-373 K),showing the great temperature measuring property especially in low temperature region.The temperature sensing characteristics are superior to the results of most previous reports.The energy transfer(ET)process is certified to occur from Ce^(3+)to Eu^(2+)ions.These studies indicate that La_(5)Si_(2)BO_(13):Ce^(3+),Eu^(2+)phosphor could have a good prospect for optical thermometry.展开更多
The Er3+doped double perovskite Ba_(2)CaWO_(6) crystal is a promising ratiometric thermometer based on the fluorescence intensity ratio(FIR) of transitions from ^(2)H_(11/2) and ^(4)S_(3/2) to the lowered ^(4)I_(15/2)...The Er3+doped double perovskite Ba_(2)CaWO_(6) crystal is a promising ratiometric thermometer based on the fluorescence intensity ratio(FIR) of transitions from ^(2)H_(11/2) and ^(4)S_(3/2) to the lowered ^(4)I_(15/2) level.However,the Ca^(2+) vacancy defect caused by the charge difference between rare-earth ions and the substituted alkaline-earth ions gives rise to the non-radiative probability and limits the thermal sensitivity.Here,the up-conversion luminescence and thermometric performance of Er^(3+),Yb^(3+) dopedBa_(2)CaWO_(6) are tuned by tri-doping with alkaline ions.The Ca^(2+) vacancy defect can be eliminated by the introduction of Na^(+),which occupies the Ca^(2+) site when it is doped into Ba_(2)CaWO_(6) with Er^(3+) and Yb^(3+).On the contrary,the doping of Cs^(+) into Ba_(2)CaWO_(6) with Er^(3+) and Yb^(3+) enhances the defect concentration because it occupies the site of Ba^(2+).Thus,the tri-doping of Na^(+) reduces the non-radiative probability and enhances the quantum efficiency of Er^(3+),leading to the improvement of the thermometric sensitivity of Ba_(2)CaWO_(6).As a result,we get an excellent thermometric Ba_(2)CaWO_(6):8%Yb^(3+),3.5%Er^(3+),6%Na^(+) powder with a luminescence lifetime of 515 μs and maximum thermal sensitivity(S_(r)) of 1.45%/K,which is more than three times higher than that of the BCWO:Er^(3+) powder.展开更多
Tb^(3+)/Eu^(3+) co-doped transparent glass ceramics containing CaF_2 nanocrystals were successfully synthesized by high temperature melt-quenching method and subsequent heating. The structure and morphology of the sam...Tb^(3+)/Eu^(3+) co-doped transparent glass ceramics containing CaF_2 nanocrystals were successfully synthesized by high temperature melt-quenching method and subsequent heating. The structure and morphology of the samples were investigated by X-ray diffraction(XRD), transmittance electron microscopy(TEM), high resolution TEM(HRTEM) and selected area electron diffraction(SAED). The photoluminescence properties and energy transfer process from Tb^(3+) to Eu^(3+) of CaF_2:Tb^(3+),Eu^(3+) phosphors were also investigated through excitation spectra and decay curves. In addition, the emission spectra of the glass ceramics in a wide temperature range from 21 to 320 K were recorded under the excitation of 485 nm. It was found that the fluorescence intensity ratios of Tb^(3+) at 545 nm(~5D_4→~7F_5) to Eu^(3+) at 615 nm(~5D_0→~7F_2) was highly temperature-dependent with an approximate linear relationship, and the temperature sensitivity was about 0.4%/K. It is expected that the investigated Tb^(3+)/Eu^(3+) co-doped CaF_2 glass ceramics may have prospective application in optical thermometry.展开更多
Eu^(2+)/Sm^(3+)co-doped dual-emitting Sr_(4)La(PO_(4))_(3)O phosphors were synthesized through a convenient high temperature solid state reaction in reductive atmosphere.The structure,luminescence,energy transfer and ...Eu^(2+)/Sm^(3+)co-doped dual-emitting Sr_(4)La(PO_(4))_(3)O phosphors were synthesized through a convenient high temperature solid state reaction in reductive atmosphere.The structure,luminescence,energy transfer and temperature-dependent luminescence properties of Eu^(2+)/Sm^(3+)co-doped Sr_(4)La(PO_(4))_(3)O phosphors were researched and analyzed in detail.The blue emission of Eu^(2+)and the red emission of Sm^(3+)can work together as FIR signals.Based on the different response characteristics of these two ion emissions to temperature,Sr_(4)La(PO_(4))_(3)O:Eu^(2+)/Sm^(^(3+))phosphor achieves the relative sensitivity of0.48384%/K and a wide range of temperature measurements from room temperature to 573 K.The results reveal that the Sr_(4)La(PO_(4))_(3)O:Eu^(2+)/Sm^(3+)phosphor has application prospect in the field of high temperature optical thermometry.The energy transfer mechanism is proved to be the dipole-dipole interaction between Eu^(2+)and Sm^(3+)ions.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52072101,51972088,52172205)the Fundamental Research Funds for the Provincial Universities of Zhejiang(No.GK229909299001-003)the Postgraduate Research Innovation Fund of Hangzhou Dianzi University(No.CXJJ2022032)。
文摘Optical thermometry as an important local temperature-sensing technique,has received increasing attention in scientific and industrial areas.However,it is still a big challenge to develop luminescent materials with self-activated dual-wavelength emissions toward high-sensitivity optical thermometers.Herein,a novel ratiometric thermometric strategy of Bi^(3+)-activated dual-wavelength emission band was realized in the same lattice position with two local electronic states of La_(3)Sb_(1-x)Ta_xO_(7):Bi^(3+)(0≤x≤1.0)materials based on the different temperature-dependent emission behaviors,benefiting from the highlysensitive and regulable emission to the coordination environment of Bi^(3+).The structural and spectral results demonstrate that the emission tremendously shifted from green to blue with 68 nm and the intensity was enhanced 2.6 times.Especially,the visual dual-wavelength emitting from two emission centers was presented by increasing the Ta^(5+)substitution concentration to 20%or 25%,mainly originating from the two local electronic states around the Bi^(3+)emission center.Significantly,the dual-wavelength with different thermal-quenching performance provided high-temperature sensitivity and good discrimination signals for optical thermometry in the range between 303 and 493 K.The maximum relative sensitivity reached 2.64%/K(La_(3)Sb_(0.8)Ta_(0.2)O_(7):0.04Bi^(3+)@383 K)and 1.91%/K(La_(3)Sb_(0.75)Ta_(0.25)O_(7):0.04Bi^(3+)@388 K).This work reveals a rational design strategy of different local electronic states around the singledoping multiple emission centers towards practical applications,such as luminescence thermometry and white LED lighting.
基金This work was financially supported by the National Natural Science Foundation of China(No.61865003)Project of Guangxi Key Laboratory of Information Materials(No.211009-Z).
文摘In order to meet the needs of new materials gradually developing towards miniaturization,integration,and light weight,multifunctional BaNb_(2)O_(6):Yb^(3+)/Er^(3+)/Tm^(3+)transparent glass-ceramics were success-fully prepared by melt quenching and controllable crystallization.Its structure,luminescence,and en-ergy transmission were studied.Using the opposite temperature dependence of the Tm^(3+)emission band and the corresponding large energy level gap,a maximum relative sensitivity of 2.3%K^(-1)based on thermal coupling levels(TCLs)is obtained in a wide temperature range(298-673 K).The multi-ratio optical thermometry based on TCLs and non-TCLs is successfully realized by using the different emission bands of double emission centers,which makes it possible for self-reference optical temperature measurement modes.In addition,the transparent glass-ceramic exhibits excellent electrical properties under 700 kV cm^(-1)electric field:high discharge energy density(W_(d)=0.99 J cm^(-3)),huge instantaneous power density(225.3 MW cm^(-3)),and ultra-fast discharge rate(T_(0.9)≤15.8 ns).The prepared glass-ceramic is expected to be a new type of lead-free multifunctional photoelectric material for temperature sensors and transparent electronic devices.
基金Project supported by Natural Science Foundation of Zhejiang Province,China(LY19E020005)Science and Technology Innovation Platform and Talent Plan of Zhejiang(2017R52037)。
文摘A novel non-contact optical thermometer,qualified with high sensitivity and temperature resolution,is urgently needed for temperature measuring of micro devices,moving objects and specific severe environments.Hence,a series of dual-emitting La_(5)Si_(2)BO_(13):Ce^(3+),Eu^(2+)phosphors were synthesized.The two ions show diverse responses with the changing in temperature.The variational emissions of Ce^(3+)and Eu^(2+)can be converted to FIR(fluorescence intensity ratio)signals.The maximal absolute sensitivity Sa and relative sensitivity Sr reach up to 0.07526%/K and 3.2241%/K,respectively.It is worthy noting that the Sa and Sr possess the same variation tendency and both have high values in the low temperature region(293-373 K),showing the great temperature measuring property especially in low temperature region.The temperature sensing characteristics are superior to the results of most previous reports.The energy transfer(ET)process is certified to occur from Ce^(3+)to Eu^(2+)ions.These studies indicate that La_(5)Si_(2)BO_(13):Ce^(3+),Eu^(2+)phosphor could have a good prospect for optical thermometry.
基金Project supported by the National Natural Science Foundation of China (51972061,22109025,22171045,52072076)。
文摘The Er3+doped double perovskite Ba_(2)CaWO_(6) crystal is a promising ratiometric thermometer based on the fluorescence intensity ratio(FIR) of transitions from ^(2)H_(11/2) and ^(4)S_(3/2) to the lowered ^(4)I_(15/2) level.However,the Ca^(2+) vacancy defect caused by the charge difference between rare-earth ions and the substituted alkaline-earth ions gives rise to the non-radiative probability and limits the thermal sensitivity.Here,the up-conversion luminescence and thermometric performance of Er^(3+),Yb^(3+) dopedBa_(2)CaWO_(6) are tuned by tri-doping with alkaline ions.The Ca^(2+) vacancy defect can be eliminated by the introduction of Na^(+),which occupies the Ca^(2+) site when it is doped into Ba_(2)CaWO_(6) with Er^(3+) and Yb^(3+).On the contrary,the doping of Cs^(+) into Ba_(2)CaWO_(6) with Er^(3+) and Yb^(3+) enhances the defect concentration because it occupies the site of Ba^(2+).Thus,the tri-doping of Na^(+) reduces the non-radiative probability and enhances the quantum efficiency of Er^(3+),leading to the improvement of the thermometric sensitivity of Ba_(2)CaWO_(6).As a result,we get an excellent thermometric Ba_(2)CaWO_(6):8%Yb^(3+),3.5%Er^(3+),6%Na^(+) powder with a luminescence lifetime of 515 μs and maximum thermal sensitivity(S_(r)) of 1.45%/K,which is more than three times higher than that of the BCWO:Er^(3+) powder.
基金supported by the National Key Research and Development Program of China(2021YFE0105700)the National Natural Science Foundation of China(52302177 and 51972118)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01X137)。
基金Project supported by the National Key Basic Research Program of China(2013CB921800)the National Natural Science Foundation of China(11274299,11374291,11574298,11404321)
文摘Tb^(3+)/Eu^(3+) co-doped transparent glass ceramics containing CaF_2 nanocrystals were successfully synthesized by high temperature melt-quenching method and subsequent heating. The structure and morphology of the samples were investigated by X-ray diffraction(XRD), transmittance electron microscopy(TEM), high resolution TEM(HRTEM) and selected area electron diffraction(SAED). The photoluminescence properties and energy transfer process from Tb^(3+) to Eu^(3+) of CaF_2:Tb^(3+),Eu^(3+) phosphors were also investigated through excitation spectra and decay curves. In addition, the emission spectra of the glass ceramics in a wide temperature range from 21 to 320 K were recorded under the excitation of 485 nm. It was found that the fluorescence intensity ratios of Tb^(3+) at 545 nm(~5D_4→~7F_5) to Eu^(3+) at 615 nm(~5D_0→~7F_2) was highly temperature-dependent with an approximate linear relationship, and the temperature sensitivity was about 0.4%/K. It is expected that the investigated Tb^(3+)/Eu^(3+) co-doped CaF_2 glass ceramics may have prospective application in optical thermometry.
基金Project supported by Natural Science Foundation of Zhejiang Province,China(LY19E020005)Science and Technology Innovation Platform and Talent Plan of Zhejiang(2017R52037)。
文摘Eu^(2+)/Sm^(3+)co-doped dual-emitting Sr_(4)La(PO_(4))_(3)O phosphors were synthesized through a convenient high temperature solid state reaction in reductive atmosphere.The structure,luminescence,energy transfer and temperature-dependent luminescence properties of Eu^(2+)/Sm^(3+)co-doped Sr_(4)La(PO_(4))_(3)O phosphors were researched and analyzed in detail.The blue emission of Eu^(2+)and the red emission of Sm^(3+)can work together as FIR signals.Based on the different response characteristics of these two ion emissions to temperature,Sr_(4)La(PO_(4))_(3)O:Eu^(2+)/Sm^(^(3+))phosphor achieves the relative sensitivity of0.48384%/K and a wide range of temperature measurements from room temperature to 573 K.The results reveal that the Sr_(4)La(PO_(4))_(3)O:Eu^(2+)/Sm^(3+)phosphor has application prospect in the field of high temperature optical thermometry.The energy transfer mechanism is proved to be the dipole-dipole interaction between Eu^(2+)and Sm^(3+)ions.
