luminescence

摘要： Cr^(3+)-activated far-red and near-infrared phosphors have drawn considerable attention owing to their adjustable emission wavelengths and wide applications.Herein,we reported a series of Cr^(3+)-doped phosphors withβ-Ca_(3)(PO_(4))_(2)-type structure,of which Ca_(9)Ga(PO_(4))_(7):Cr^(3+) possessed the highest far-red emission intensity.At an excitation of 440 nm,the Ca_(9)Ga(PO_(4))_(7):Cr^(3+) phosphors exhibited a broad emission band ranging from 650 to 850 nm and peaking at 735 nm,and the broadband superimposed two sharp lines centering at 690 and 698 nm.The optimal sample Ca_(9)Ga_(0.97)(PO_(4))_(7):0.03 Cr^(3+) had an internal quantum efficiency of 55.7%.The luminescence intensity of the Ca_(9)Ga_(0.97)(PO_(4))_(7):0.03 Cr^(3+) phosphor obtained at 423 K could maintain 68.5%of that at room temperature,demonstrating its outstanding luminescence thermal stability.A phosphor-conversion light-emitting diode was fabricated,indicating that the Ca_(9)Ga(PO_(4))_(7):Cr^(3+) phosphor has potential applications in indoor plant cultivation.

摘要： An interesting phenomenon was found that fluorophore was introduced into ionic liquid(IL)to magnify fluorescence signal via the thermally activated delayed fluorescence process;thus up to 15 fold enhancements were achieved.Hence,we reported a succinct enhanced luminescence strategy to reduce single-triplet energy split by the tunability of ILs.This strategy could be extended to more kinds of ILs by the virtue of a preliminary DFT calculation screening.Moreover,the optical feature of IL sensor made it a promising candidate as a gas fluorescence sensor.

摘要： The understanding of amphiphilic block copolymers(ABC)in encapsulation and transport of inorganic nanomedicines is highly desired.Still,it remains limited due to the challenges in the fabrication of nanoassemblies(NAs)with highly-controlled shape and loading of nanoparticles.Herein,through growth regulation of luminescent gold nanoparticles(Au NPs)by different reductants with ABC pluronic F127 as a template,a straightforward strategy is reported for in-situ fabrication of three wellcontrolled gold NAs(Au NAs)that display tunable shapes from spherical to elongated nanostructures and controllable surface chemistry and loading of Au NPs with distinct emissions but identical individual Au NP size.The three Au NAs exhibit tailored invivo transport behaviours:those with spherical shape and more hydrophilic surface show longer blood retention with higher tumor-targeting efficiency(~25.3%injection dose/g)and excellent long-term near-infrared tumor imaging even after 96 h postinjection.These findings provide a useful guidance in designing specific nanostructures for future nanomedicine transport.

摘要： Electroluminescence of f-f transition lanthanide complex is a traditional topic for display over decades.Here we report highly efficient organic light-emitting diodes based on a new terbium(III)complex with novel ligand CPMIP(1-(4-cyanophenyl)-3-methyl-4-isobutyryl-pyrazoline-5-one).The high triplet energy level of CPMIP(3.0 e V)and inhibited quenching effects in the solid-state lead to a nearly 100%photoluminescent quantum efficiency of Tb(CPMIP)3.The best Tb(CPMIP)3 device exhibited maximum external quantum efficiency up to 19.7%,setting a new record of OLEDs based on f-f transition lanthanide complexes.

摘要： Isolating reductive silver kernel from shell is a challenging task but is quite important to understand the embryonic form during the formation of silver nanoclusters.The intercalation of suitable anionic species may be of benefit for passivating then capturing such highly active kernel.Herein,we successfully isolated a novel silver thiolate nanocluster[Ag_(13)@Ag_(76)S_(16)(Cyh S)_(42)(p-NH_(2)-Ph As O_(3))_(4)]^(3+)(SD/Ag89 a,Cyh SH=cyclohexanethiol)that contains a well-isolated icosahedral Ag_(13) kernel passivated by four Ag S_(4)^(7-) tetrahedra and four p-NH_(2) Ph As O_(3)^(2-) piercing from outer Ag_(72) shell.Of note,this Ag_(13) kernel is the largest isolable subvalent silver kernel beneath the silver shell with extremely legible core-shell boundary ever before and represents a precise embryonic model formed in the reducing Ag(I)to Ag(0)followed by aggregating to large silver nanoparticles.The reductive role of DMF and the introduction of anionic passivation layer(APL)synergistically modulate the reduction kinetics,facilitating the capture of ultrasmall subvalent silver kernel.SD/Ag89 a emits in near infrared(NIR)region(λ_(em)=800 nm)at low temperature.The synthetic strategy shown in this work opens up new opportunities for precisely capturing and recognizing diverse reductive silver kernels in different systems.

摘要： Open metal site(OMS)seated in a luminescent lanthanide(Ln)metal center offers an opportunity for rationally tuning the spectroscopic behavior of lanthanide-organic frameworks aiming for a wide range of sensing applications.However,given the spherical nature of common coordination geometries of trivalent lanthanides and the generally strong Ln–O bonds,the lanthanide based OMS is rarely reported and difficult to be functionalized.We report here a unique europium-organic framework containing abundant quasi-OMS that is protected by an abnormal weak Eu–O bond.These quasi-OMSs offer reversible direct binding sites for water molecules probed by X-ray crystallography,leading to sensitive,visible,and ratiometric luminescent sensing toward humidity and water content in organic solvents.The specific recognition of water based on quasi-luminescentOMSs gives rise to a superior water detection limit down to 0.0003%v/v,which is one order of magnitude lower than that of Karl Fischer method.

摘要： In the development of new optoelectronic devices, mainly those related to solid state technology (SSL), the generation of luminescent materials with high intensity in visible region and low cost is of vital importance. For this reason, this work presents the luminescent properties of zinc phosphate glasses doped with the manganese ion 2+. The manganese ion offers a series of advantages with respect to rare earths, such as a more accessible cost and an intense emission in the red color that make it a great candidate for the generation of new optoelectronic devices. The methodology for the synthesis is presented in this work, as well as its luminescent properties, for concentrations of 2%, 10%, 13% and 15% atomic.

摘要： Rare-earth doped inorganic ferroelectrics are considered as novel photochromic materials,with potential applications for optical switch and information storage(K0.5Na0.5)1–xEuxNbO3(KNN:xEu)ceramics were prepared by high temperature calcination,with precursor powder obtained by hydrothermal method.Strong red emission at 615 nm was observed which corresponds to the 5D0→7F2 transition of Eu3+under excitation of 465 nm.Under UV light irradiation for 3 min,the color of the ceramics turned from milky white to dark gray.The colored samples returned to the original color when heated at 200°Cfor 10 min,showing strong photochromic behavior.Meanwhile,the luminescence intensity of Eu3+can be tuned without obvious degradation by alternating UV light and heat stimulus.Upon UV light irradiation,large luminescence modulation ratio(ΔRt)up to 83.9%was achieved for KNN:0.06Eu,indicating good luminescence switching behavior.A possible mechanism for non-radiative energy transfer from the luminescent center to the color center was proposed according to their luminescent behavior.

摘要： KF-KYb3F10:Tm nano complex was synthesized by low-temperature hydrothermal method.The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The effect of the annealing temperatures on the upconversion luminescence intensity was investigated.The results indicated that the prepared KF-KYb3F10:Tm nano complex was about 50 nm spherical luminous powder.Under the excitation of 980nm laser (LD),the upconversion emission peaks located at 445 nm,536 nm and 660 nm,respectively.The upconversion luminescence mechanism was discussed.