Ultra-stable Eu3+-doped CsPbCl2Br1 perovskite quantum dots glass for optical temperature sensing

In this work, Eu³⁺-doped CsPbCl₂Br₁ in borosilicate glass was successfully synthesized by the melt quenching annealing technique and crystallization method. This work reports a novel Eu³⁺-doped CsPbCl₂Br₁ perovskite quantum dots (QDs) glass with high sensitivity for optical temperature sensing. The relation of fluorescence intensity ratio (FIR) with the temperature was studied in the temperature range of 80–440 K. Notably, the maximum absolute temperature sensitivity (S_a) and relative temperature sensitivity (S_r) of Eu³⁺-doped CsPbCl₂Br₁ perovskite QDs glass can reach as high as 0.0315 K^–1 and 3.097%/K, respectively. Meanwhile, Eu³⁺-doped CsPbCl₂Br₁ QDs glass demonstrates good water resistance, excellent thermal and cold cycling stability performance. The Eu³⁺-doped QDs glass materials can bring inspiration to the future exploration of rare earth ion-doped QDs glass material on the application of optical temperature sensing in the future.     

Luminescent properties of Tb~(3+) doped high density borogermanate scintillating glasses

Tb~(3+)-doped high density borogermanate glasses were prepared by melt-quenching method. Their physical and luminescent properties including differential thermal analysis(DTA), density, transmittance spectra, photoluminescence, and X-ray excited luminescence spectra were investigated. The densities of the glasses doped with Tb~(3+) were in the range from 5.690 to 6.086 g/cm~3. Under UV and X-ray excitations, the glasses showed intense green emissions. The lifetimes of Tb~(3+) doped borogermanate glasses were in the range from 1.597 to 1.869 ms. The results indicated that Tb~(3+) doped borogermanate glasses could be scintillator candidate used in X-ray detection application.     

Sub-10 nm lanthanide-doped SrFCl nanoprobes:Controlled synthesis,optical properties and bioimaging

Alkaline-earth dihalide nanocrystals(NCs) such as SrFCl, owing to their high chemical stability and low phonon energy, are excellent host materials for lanthanide(Ln~(3+)) doping to achieve desirable optical properties for various bioapplications, Herein, we report a novel strategy for the synthesis of sub-10 nm Ln~(3+)-doped SrFCl NCs with efficient upconverting and downshifting luminescence through a facile onestep hot-injection method. Utilizing the temperature-dependent upconverting luminescence(UCL) from the thermally coupled ~2H_(11/2) and ~4S_(3/2) levels of Er~(3+), we showed the potential of SrFCl:Yb,Er NCs as sensitive UCL nanoprobes for non-contact thermal sensing with a maximum detection sensitivity of 0.0066 K~(-1), which is among the highest values for thermal sensing based on Er~(3+)-activated UCL nanoprobes. Furthermore, by employing the intense downshifting luminescence from Tb~(3+) and Eu~(3+), we demonstrated the successful use of biotinylated SrFCl:Ce,Tb and SrFCl:Eu~(3+) nanoprobes for biotin receptor-targeted cancer cell imaging, thus revealing the great promise of SrFCl:Ln~(3+) nanoprobes for versatile bioapplications.     

Tunable luminescence,energy transfer and excellent thermal stability of SrMg_2(PO_4)_2:Ce~(3+),Tb~(3+) phosphors for LEDs

A series of novel SrMg_2(PO_4)_2:Ce~(3+),Tb~(3+)(SMP:Ce~(3+),Tb~(3+)) phosphors with tunable emission spectra were produced via high temperature solid phase method.XRD,fluorescence spectrum and fluorescence lifetime for SMP:Ce~(3+),Tb~(3+)were studied in detail.Under the excitation at 308 nm,SMP:Ce~(3+),Tb~(3+) samples can emit high efficiency tunable blue-green light by controlling the proportion of dopant concentration.Through the spectral overlap and the regular change of fluorescence lifetime,it is proved that there is a significant energy transfer between Ce~(3+) and Tb~(3+) in SMP matrix and the energy transfer mechanism is determined to be an electric dipole-dipole interaction with energy transmission efficiency of 55%.In additional,Commission International de L'Eclairage(CIE) color coordinates and thermal stability were studied.All above findings suggest that SMP:Ce~(3+),Tb~(3+)can be regarded as the potential bluish green phosphor for LED applications.     

Influence of coating on the photoluminescence of Tb~(3+) doped ZnS e/ZnS core-shell quantum dots

Tb~(3+)-doped ZnSe and ZnSe/ZnS nanocrystals were synthesized using modified hot-injection method.The observation of the characteristic quantum dots absorption features in a time-gated excitation spectrum was recorded while monitoring Tb~(3+) emission at 545 nm provided direct evidence for successful incorporation of dopant ions into semiconductor host.Relatively long decay time(~1.5 ms) of Tb~(3+) emission indicated that dopant ions were well protected from interaction with surface ligands.Emission properties of core ZnSe:Tb~(3+) nanocrystals were only slightly modified upon growth of ZnS shell..     

Na_2WO_4:Eu~(3+),Tb~(3+)光致发光材料的发光性质和能量传递

利用溶胶-凝胶法,将激活离子Eu~(3+)和Tb~(3+)以单一或混合的形式掺入体系得到了光致发光材料.分别研究了材料中激活离子Eu~(3+)和Tb~(3+)的含量及其离子之间的能量传递关系.主要利用材料的三维荧光光谱,激发光谱和发射光谱对其的发光性质进行了分析;结果发现,材料中有两个发光中心,分别为Eu~(3+)和Tb~(3+),在不同的波长光的激发下得到的材料的红绿色发光强度不同,而且Eu~(3+)和Tb~(3+)的掺杂浓度比对发光色度影响很大.所以可以根据选择最适合的Eu~(3+)和Tb~(3+)的浓度比来控制材料的发光色,也可以通过不同的激发波长对材料的色度进行微调.     

Monolithic crystalline silicon solar cells with SiN_x layers doped with Tb~(3+) and Yb~(3+) rare-earth ions

In this study, we propose the fabrication of monolithic crystalline silicon solar cells with Tb~(3+) and Yb~(3+)-doped silicon nitride(SiN_x) layers by low-cost screen-printing methods. The performances of c-Si solar cells can be enhanced by rare-earth ions doped SiN_x layers via the mechanism of spectrum conversion.These SiN_x doped and codoped thin films were deposited by reactive magnetron co-sputtering and integrated as the antireflection coating layers in c-Si solar cells. The characterizations of SiN_x, SiN_x:Tb~(3+) tand SiN_x:Tb~(3+)-Yb~(3+) thin films were conducted by means of photoluminescence, Rutherford backscattering spectroscopy, Ellipsometry spectroscopy and Fourier transform infrared measurements. Their composition and refractive index was optimized to obtain good anti-reflection coating layer for c-Si solar cells.Transmission electron microscopy performs the uniform coatings on the textured emitter of c-Si solar cells. After the metallization process, we demonstrate monolithic c-Si solar cells with spectrum conversion layers, which lead to a relative increase by 1.34% in the conversion efficiency.     

Energy transfer in co-and tri-doped Y_3Al_5O_(12) phosphors

Single-doped(Ce~(3+),Tb~(3+)), co-doped(Ce~(3+)-Tb~(3+), Ce~(3+)-Yb~(3+), Tb~(3+)-Yb~(3+)) and tri-doped(Ce~(3+)-Tb~(3+)-Yb~(3+)) Y_3Al_5O_(12) phosphors were synthesized by a solid-state reaction method. The XRD, excitation and emission spectra and the fluorescence lifetime of the samples were measured. The energy transfer mechanism was also investigated. The results showed that the energy transfer efficiency from Tb~(3+) to Ce~(3+) was 51% and the energy transfer efficiency from Ce~(3+) to Yb~(3+) was 63.1%. Concomitantly, both were more efficient than that from Ce~(3+) to Tb~(3+)(7%) and from Tb~(3+) to Yb~(3+)(10.2%). Also, the Yb~(3+) ions received energy mainly from Ce~(3+) ions in Ce~(3+)-Tb~(3+)-Yb~(3+) tri-doped Y_3Al_5O_(12) phosphors. Among these materials, Ce~(3+)-Yb~(3+) co-doped YAG phosphors are a better choice than others as a down-conversion material due to their higher energy transfer efficiency.     

A terbium activated multicolour photoluminescent phosphor for luminescent anticounterfeiting

The multicolor photoluminescence(PL) of a Tb~(3+)singly activated NaYGeO_4 phosphor is prepared by solid state method.For the first time,it is reported that the PL color of Tb~(3+)in NaYGeO_4 phosphor can be tuned from green to blue and,finally,to red by controlling the Tb~(3+)content.The optimal tricolor phosphors are NaYGeO_4:0.01 mol% Tb~(3+)(red),NaYGeO_4:0.5 mol% Tb~(3+)(blue) and NaYGeO4:5 mol% Tb~(3+)(green),respectively.The PL properties of the NaYGeO_4:Tb~(3+) phosphor were studied in details.The results reveal that the PL color modulations of the NaYGeO_4:Tb~(3+)phosphor are essentially due to the cross-relaxation effect of Tb~(3+),and a possible mechanism on the cross-relaxation is proposed.According to these unique features,a multicolor PL image was fabricated based on the NaYGeO_4:Tb~(3+) phosphor for potential applications in luminescent anticounterfeiting.     

Synthesis,optical properties,and energy transfer of Ce~(3+),Tb~(3+) doped KLu_2F_7

Ce~(3+), Tb~(3+) doped orthorhombic phases of KLu_2F_7 microcrystals with hexagonal disk morphology were synthesized by a hydrothermal method. Enhanced emissions of Tb~(3+) were observed in the Ce~(3+)/Tb~(3+) co-doped KLu_2F_7 sample compared to the Tb~(3+) single-doped KLu_2F_7. The energy transfer efficiency from Ce~(3+) to Tb~(3+) was calculated by the photoluminescence intensity in the Ce~(3+)/Tb~(3+) co-doped KLu_2F_7 samples. The average separations between Ce~(3+) and Tb~(3+) were calculated and the critical distance was 0.922 nm estimated by method of concentration quenching. The theoretical calculation proved the results. The theoretical analysis also suggested that the energy transfer from Ce~(3+) to Tb~(3+) in the KLu_2F_7 occurred predominantly via the dipole-quadrupole interaction. The KLu_2F_7 should be good host materials for emitters.     

Eu3+、Tb3+、Dy3+与L-脯氨酸、甘氨酸、L-丙氨酸四元固态配合物的荧光光谱研究

对在水中合成的稀土元素(Eu 、Tb 、Dy)与L-脯氨酸(L-Pro)、甘氨酸 (Gly)、L-丙氨酸(L-Ala)四元固态配合物的荧光光谱进行了研究.结果表明铕、铽配合物的荧光强度均较其相应的盐高(铕高出4.5倍,铽高出9倍);四元配合物的荧光强度较三元配合物有不同程度的提高;四元配合物中,铽的荧光强度较铕的荧光强度高出近11倍.同时对上述实验结果进行了解释.     

Tunable luminescence and energy transfer in Y_2BaAl_4SiO_(12):Tb~(3+),Eu~(3+)phosphors for solid-state lighting

Single-phase Y₂BaAl₄SiO₁₂:Tb³⁺,Eu³⁺phosphors with adjustable luminescence were successfully prepared by high-temperature solid-state reaction method.The structural,luminescent properties and ene rgy transfer(ET) process of Y₂BaAl₄SiO₁₂:Tb^(³⁺),Eu³⁺phosphors were syste matically analyzed with the help of X-ray diffraction(XRD),scanning electron microscopy(SEM),excitation spectra,emission spectra and photoluminescence decay curves.Tunable luminescence ranging from green through yellow and definitively to red can be achieved by elevating amounts of Eu³⁺ions in Tb³⁺,Eu³⁺co-doped samples.Besides,the ET mechanism and efficiency were also analyzed and the maximum ET efficiency is 67%.All the results show that Y₂BaAl₄SiO₁₂:Tb³⁺,Eu³⁺phosphors can be used in solid-state lighting.     

Synthesis and Properties of Tb^3＋-Doped CaxSr1-xWO4

Tb^3 -doped CaxSr1-xWO4 was prepared by solid state reaction and characterized by powder X-ray diffractometry. According to X-ray diffraction, this material belongs to tetragonal system, which is consistent with space group 141/α. Lattice parameters in the systems CaxSr1-xWO4 were found to vary linearly with compositions. The emission and excitation spectra were measured. The miscibility, luminescence properties of Tb^3 -doped CaxSr1-xWO4 and energy transfer mechanism were discussed.     

Temperature sensing behavior of Tm~(3+):~1G_4(a),~1G_4(b) in oxyfluoride glass ceramics containing BaYb_xY_(1-x)F_5 nanocrystals

Tm~(3+)-doped transparent oxyfluoride glass ceramics containing BaYb_xY((1-x))F_5 nanocrystals were prepared via high temperature solid phase melting method,of which up-conversion emission is achieved by the Yb~(3+)-mediated energy transfer process.The required photon number of Tm~(3+)ions emissions in BaYb_xY_((1-x))F_5 nanocrystals was calculated through the luminescence spectra,revealing the strong dependence of energy transfer mechanism on Yb~(3+)ions concentration.Meanwhile,based on the fluore scence intensity ratio technology,the effect of different energy transfer mechanism on the temperature sensitivity was investigated by the temperature-dependent luminescence intensity of thermally coupled energy levels of Tm~(3+):~1G_4(a),~1G_4(b).The obtained sensitivity decreases with the increase of Yb~(3+)ions content,which is mainly attributed to the changes in photon absorption process of Tm~(3+):~1G_4(b).     

Sensitizing effect of Nd~(3+) on Tb~(3+) activated ZrP_2O_7 long persistent phosphor materials

The long persistent phosphors of Zr_(0.97)P_2 O_7:0.018 Tb~(3+),0.012 Nd3+with Nd~(3+)as sensitized ions and Tb~(3+)as emission centers were synthesized using high temperature solid state reaction.The crystal structure and defects,excitation and emission spectra,decay curves and thermoluminescence(TL) curves of the phosphors were investigated.The synthesized Zr_(0.97)P_2 O_7:0.018 Tb3+,0.012 Nd3+is essentially in line with the standard card PDF#49-1079.The emission band with main peak at 548 nm exhibits the characteristic transitions of ~5 D_3-~7 F_j(j=5,4) and ~5 D3-~7 F_j(j=6,5,4,3) of Tb~(3+).The analysis of excitation and emission spectra shows that there exists the overlap between the emission peaks of Nd~(3+)at 466 and 485 nm and the excitation of Tb3+at 443 and 485 nm,and the energy transfer from Nd3+to Tb3+plays an important role in the improvement of luminescence properties.The decay curves shows that Zr_(0.97)P_2 O_7:0.018 Tb3+,0.012 Nd3+has longer afterglow time than ZrP_2 O_7 and Zr_(0.982)P_2 O_7:0.018 Tb3+.Additionally,the TL curves indicate that the trap depth at 0.72 eV in Zr_(0.97)P_2 O_7:0.018 Tb~(3+),0.012 Nd3+is to the benefit of the afterglow time.The possible luminescence mechanism of ZrP_2 O_7:Tb~(3+),Nd3+is proposed on the basis of the XPS spectra,EPR spectra,excitation and emission spectra,decay curves,TL curves and the analysis of defect equations.     

Luminescent and thermometric properties of dual emitting Eu~(2+)/Sm~(3+) co-doped Sr_4La(PO_4)_3O phosphor based on energy transfer

Eu²⁺/Sm³⁺co-doped dual-emitting Sr₄La(PO₄)₃O 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 Eu²⁺/Sm³⁺co-doped Sr₄La(PO₄)₃O phosphors were researched and analyzed in detail.The blue emission of Eu²⁺and the red emission of Sm³⁺can work together as FIR signals.Based on the different response characteristics of these two ion emissions to temperature,Sr₄La(PO₄)₃O:Eu²⁺/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 Sr₄La(PO₄)₃O:Eu²⁺/Sm³⁺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 Eu²⁺and Sm³⁺ions.     

Near-infrared luminescent Nd~(3+)/Yb~(3+)-codoped metal-organic framework for ratiometric temperature sensing in physiological range

Self-calibrating luminescent thermometry employing luminescence within the optical transparency windows provides a promising prospect for temperature measurement in the biological fields.In this work,a new Nd~(3+)/Yb~(3+)-codoped metal-organic framework Nd_(0.95)Yb_(0.05)BPTC showing threedimensional anionic network,obtained by reacting ligand [1,1'-biphenyl]-3,3',5,5'-tetracarboxylic acid(H_4BPTC) with Nd~(3+) and Yb~(3+) ions under solvothermal conditions,is reported.Upon 808 nm photoexcitation,Nd_(0.95)Yb_(0.05)BPTC simultaneously emits the characteristic near-infrared luminescence of Nd~(3+) and Yb~(3+) ions based on the efficient energy transfer from Nd~(3+) to Yb~(3+) ions.In addition,the emission intensity ratio of Yb~(3+) and Nd~(3+) shows good exponential-like response to temperature in the physiological range of 293-323 K.The feature properties of Nd_(0.95)Yb_(0.05)BPTC include near-infrared absorption and emission,favorable temperature sensitivity and accurate temperature uncertainty,as well as good chemical stability,making such system useful in biomedical applications.     

X-ray-activated UVA long persistent luminescence from defective fluoride elpasolites

Long persistent phosphors have received significant attention owing to their attractive photophysical properties.Here,we report a new long persistent phosphor exhibiting strong ultraviolet A(UVA)afterglow.The phosphors were synthesized by a solid-state reaction method.We find that the obtained phosphors demonstrate super long UVA-afterglow emissions after irradiation by X-ray source,and the afterglow can last more than 50 h.A wide range of experimental characterizations indicate that the Tb~(3+)doped fluoride elpasolite phosphors are defective and some fluoride ions are replaced by oxygen ions,which creates electron traps with suitable trap depths.Our results establish that Tb3+can act as optical emitters in wide-bandgap hosts that can result in the UVA afterglow.This work enriches the bank of UV long persistent phosphors,and may stimulate more efforts for the design and synthesis of this kind of optical materials.     

稀土离子与钙调素相互作用的研究进展

稀土离子由于配位环境与钙离子具有相似性,能够取代钙离子与钙调素发生作用,对钙调素的结构、构象及生物功能产生影响。各种光谱及生物化学实验研究表明,不同稀土离子与钙调素作用时,在作用力的强弱程度、结合位点、结合序及结合位点的相互作用具有各自的特殊性,本文概述了稀土离子La3+、Ce3+、Pr3+、Nd3+、Sm3+、Eu3+、Gd3+、Tb3+、Ho3+、Er3+和Lu3+等与钙调素的相互作用及对钙调素生物功能产生的影响。     

Effect of acceptor ions concentration in lead phosphate glasses co-doped with Tb~(3+)-Ln~(3+)(Ln=Eu,Sm)for LED applications

In this work,lead phosphate glasses doubly doped with Tb~(3+) and Ln~(3+)(Ln=Eu,Sm) ions were prepared.The excitation and emission spectra of lanthanides ions were recorded.The luminescent properties of lead phosphate glasses containing various concentrations of acceptor ions were analyzed.It is observed that luminescence bands corresponding to characteristic transitions of rare earth ions are present on emission spectra measured under direct excitation of Tb~(3+).From the emission spectra,the Commission Internationale de I'Eclairage(CIE) chromaticity coordinates(x,y) were calculated in relation to potential application studied systems for white LEDs.Luminescence lifetimes were also determined based on decay measurements and discussed in details.In general,the luminescence spectra and luminescence lifetimes depend on the relative concentrations of the optically active dopants.