This investigation focuses on the utilization of cucurbit[6]uril(Q[6])as the host compound for the development of long-lasting afterglow materials.By strategically manipulating the outer surface interactions of Q[6],c...This investigation focuses on the utilization of cucurbit[6]uril(Q[6])as the host compound for the development of long-lasting afterglow materials.By strategically manipulating the outer surface interactions of Q[6],classical aggregation-caused quenching(ACQ)compounds such as fluorescein sodium(FluNa)and calcein sodium(CalNa)were transformed into afterglow materials with varying colors and durations upon exposure to ultraviolet light.This transformation was facilitated through a host-vip doping method combined with coordination with metal ions.Even at a reduced doping concentration of 5×10^(-5)wt%,the materials exhibit remarkable afterglow properties,lasting up to 2 s,with a phosphorescence lifetime of up to 150 ms.Moreover,by adjusting the concentration of the vip compound,the persistent luminescence color of the materials could be easily transitioned from orange to yellow and subsequently to green.These findings suggest that the developed afterglow materials hold significant potential for multilevel anti-counterfeiting and information encryption applications when exposed to ultraviolet light.The supramolecular assembly strategy,which relies on the outer surface interactions of cucurbit[n]uril,offers a simpler and more efficient approach to crafting multi-color luminescent materials.Additionally,this method opens avenues for enhancing the application potential of aggregation-caused quenching(ACQ)compounds in various technological domains.展开更多
The development of organic afterglow materials with high environmental stability and multi-mode luminescence remains a significant challenge in luminescent anti-counterfeiting.In this work,an organic luminescent molec...The development of organic afterglow materials with high environmental stability and multi-mode luminescence remains a significant challenge in luminescent anti-counterfeiting.In this work,an organic luminescent molecule was encapsulated within polyacrylamide microspheres and embedded in a gold nanorod-doped,ferric ion-crosslinked hydrogel exhibiting upper critical solution temperature behavior.The obtained composites exhibited fluorescence,thermally activated delayed fluorescence,and phosphorescence.Through the application of extrusion or uniaxial stretching,the orientation of the gold nanorods was modulated,enabling polarization-dependent luminescence through transverse surface plasmon resonance absorption.At 300%uniaxial strain,the polarized fluorescence intensity difference at 520 nm reached 0.29.Furthermore,ultraviolet irradiation was employed to locally disrupt the orientation of the gold nanorods,resulting in depolarization within the irradiated regions.These areas displayed non-polarized fluorescence,while the non-irradiated regions retained both emission and fluorescence polarization characteristics.Localized imprinting was employed to modulate material thickness,thereby controlling the density of gold nanorods.Thinner regions exhibited weaker transverse localized surface plasmon resonance absorption,while thicker regions showed stronger absorption,enabling the coexistence of blue–green fluorescence and polarization patterns.Local humidification effectively reduced phosphorescence intensity,enhancing the material's environmental responsiveness.The composite demonstrated excellent reversibility over multiple stretching–selfhealing cycles and pattern-switching processes,highlighting its strong potential for multidimensional optical encryption and intelligent anticounterfeiting applications.展开更多
The application of aggregation-induced emission(AIE)materials in biological imaging holds multiple significances,including improving detection sensitivity and specificity,optimizing the imaging process,expanding the s...The application of aggregation-induced emission(AIE)materials in biological imaging holds multiple significances,including improving detection sensitivity and specificity,optimizing the imaging process,expanding the scope of application,and promoting advancements in biomedical research.In this work,the propeller ligand was constructed through McMurry coupling reaction and Suzuki coupling reaction by using dimethoxybenzophenone as the starting material.Then,an imine condensation reaction was carried out in chloroform solution,using a 3:2 molar ratio of precursor to tri(2-aminoethyl)amine to synthesize C3 symmetric porous organic cage CB.The structures of the compounds were determined by nuclear magnetic resonance spectroscopy(NMR),electrospray ionization mass spectrometry(ESI-MS)and Fourier transform infrared spectroscopy(FT-IR).The optical investigation results reveal that ligand L-B and the porous organic cage C_(B) demonstrate remarkable aggregation-induced emission(AIE)properties in a tetrahydrofuran/water mixed solvent system,along with a pronounced response to tetrahydrofuran vapor stimuli.Consequently,Furthermore,given its unique cage-like structure,high quantum yield,and outstanding AIE behavior,the porous organic cage C_(B) holds promise for applications in cell imaging.展开更多
Stimuli-responsive luminescent switching materials with multifunctional properties are highly essential for advanced photonic applications,yet achieving such capabilities in halide perovskites continues to pose a sign...Stimuli-responsive luminescent switching materials with multifunctional properties are highly essential for advanced photonic applications,yet achieving such capabilities in halide perovskites continues to pose a signif-icant challenge.In this work,we explore a new water-stimuli-responsive zero-dimensional(0D)Sb-based halide of[PhPz]_(2)SbCl_(7)·2H_(2)O(PhPz=phenylpiperazine),which consists of isolated[SbCl_(6)]^(3-) octahedra in[PhPz]2+cationic matrix with vip H_(2)O molecules.Under UV excitation,[PhPz]_(2)SbCl_(7)·2H_(2)O emits intense broadband red light with maximum emission at 645 nm,and combined optical characterization and theoretical calculations confirm that this luminescence originates from self-trapped excitons(STEs).Interestingly,the free water molecules can reversibly leave and entry the crystal lattice during heating-cooling cycles accompanied by the formation of dehydrated phase,which displays strong yellow emission with maximum peak at 580 nm.Therefore,reversible luminescent switching between red and yellow emission is achieved through controllable removal and adsorption process of vip H_(2)O.By virtue of this reversible thermochromic switching,this halide can be used to detect the trace amount of water in various organic solvents and humidity of moist air.In addition,such switchable dual emission further realizes application in anti-counterfeiting and information encryption-decryption.This work deepens the understanding of structure-property relationships and expands the application range of oD metal halides.展开更多
In this work,we synthesize two luminescent Pt(Ⅱ)complexes using differentπ-conjugated bidentate ligands.Both complexes are assembled into three-dimensional(3D)networks through non-classical intermolecular interactio...In this work,we synthesize two luminescent Pt(Ⅱ)complexes using differentπ-conjugated bidentate ligands.Both complexes are assembled into three-dimensional(3D)networks through non-classical intermolecular interactions in the crystal state.Unexpectedly,substituting pyridine with the more extensivelyπ-conjugated quinoline significantly increases the dihedral angles between the phenyl and quinolyl groups of the bidentate ligands.This alteration disrupts theπ-πinteractions between molecules,resulting in distinct optical properties upon exposure to external stimuli.By integrating these complexes into polymers,we fabricate electrospun films containing luminescent nanofibers that exhibit reversible optical changes.These findings have paved the way for the development of high-performance optical encryption and anti-counterfeiting materials,achieved through the employment of simple chromophores.展开更多
Counterfeiting is still a pervasive global issue,affecting multiple industries and hindering industrial innovation,while causing substantial financial losses,reputational damage,and risks to consumer safety.From luxur...Counterfeiting is still a pervasive global issue,affecting multiple industries and hindering industrial innovation,while causing substantial financial losses,reputational damage,and risks to consumer safety.From luxury goods and pharmaceuticals to electronics and automotive parts,counterfeit products infiltrate supply chains,leading to a loss of revenue for legitimate businesses and undermining consumer trust.Traditional anti-counterfeiting measures,such as holograms,serial numbers,and barcodes,have proven to be insufficient as counterfeiters continuously develop more sophisticated replication techniques.As a result,there is a growing need for more advanced,secure,and reliable methods to prevent counterfeiting.This paper presents a novel,holistic anti-counterfeiting platform that integrates Near Field Communication(NFC)-enabled mobile applications with blockchain technology to provide an innovative,secure,and consumer-friendly authentication mechanism.Our approach addresses key gaps in existing solutions by incorporating dynamic product identifiers,which make replication significantly more difficult.The system enables consumers to verify the authenticity of products instantly using their smartphones,enhancing transparency and trust in the supply chain.Blockchain technology plays a crucial role in our proposed solution by providing an immutable,decentralized ledger that records product authentication data.This ensures that product verification records cannot be tampered with or altered,adding a layer of security that is absent in conventional systems.Additionally,NFC technology enhances security by offering unique identification capabilities,enabling real-time product verification.To validate the effectiveness of the proposed system,real-world testing was conducted across different industries.The results demonstrated the platform’s ability to significantly reduce counterfeit products in the supply chain,offering businesses and consumers a more robust and reliable authentication method.By leveraging the combined strengths of blockchain and NFC,this solution represents a significant advancement in the fight against counterfeiting,ensuring enhanced security,transparency,and consumer trust.展开更多
Low-dimensional lead-free metal halides have emerged as promising candidates for anti-counterfeiting applications,characterized by their low toxicity,diverse crystal structures,and exceptional optical properties.Conve...Low-dimensional lead-free metal halides have emerged as promising candidates for anti-counterfeiting applications,characterized by their low toxicity,diverse crystal structures,and exceptional optical properties.Conventional anti-counterfeiting technologies based on low-dimensional metal halides are often constrained by complex and time-consuming heating and solvent treatments that may insufficiently modify the luminescent characteristics of emitters,thus hindering their practical implementation in effective anti-counterfeiting strategies.In this study,we employ an innovative alloying strategy in low-dimensional zinc halides Cs_(2)ZnCl_(4) to enhance their luminescent performance.By introducing self-trapped exciton(STE)states through the alloying of Cu^(+)and Sb^(3+)ions in Cs_(2)ZnCl_(4),we achieve bright blue and red photoluminescence(PL)centered at 492 nm and 744 nm,respectively,under 266 nm excitation,with only red emission observed under 365 nm excitation.This approach enables instant and reliable anti-counterfeiting applications.This work presents new opportunities for developing robust anti-counterfeiting and information encryption/decryption technologies.展开更多
In this study,a novel Ca_(2)GaTaO_(6):Sm^(3+)phosphor was developed using the conventional hightemperature solid-phase method.The phase structure and morphology test results of phosphor indicate that the Ca_(2)GaTaO_(...In this study,a novel Ca_(2)GaTaO_(6):Sm^(3+)phosphor was developed using the conventional hightemperature solid-phase method.The phase structure and morphology test results of phosphor indicate that the Ca_(2)GaTaO_(6):Sm^(3+)material was successfully synthesized and the Sm^(3+)ions were successfully doped into the host lattice.When utilizing 406 nm excitation,the Ca_(2)GaTaO_(6):Sm^(3+)phosphor has the strongest emission intensity at 599 nm and shows orange-red emission,which is mainly owing to the^(4)G_(5/2)→^(6)H_(7/2)jump of Sm^(3+)ions.For the performance of different concentrations of Sm^(3+)ions,3 mol%performs the best.At this time,concentration quenching occurs,which is most predominantly induced by dipole-dipole(d-d)interactions.In terms of thermal stability,the Ca_(2)GaTaO_(6):Sm^(3+)phosphor shows good properties,with the luminescence intensity at 423 K exhibiting 88.17%of that at 298 K.The white light-emitting diodes(WLEDs)devices prepared using Ca_(2)GaTaO_(6):Sm^(3+):0.03Sm^(3+)phosphor shows warm white light with excellent performance in terms of correlated color temperature and color rendering index(CCT=3642 K,CRI,Ra=93.5).In terms of anticounterfeit inks,the Ca_(2)GaTaO_(6):Sm^(3+)phosphor also shows good potential.These research results show that Ca_(2)GaTaO_(6):Sm^(3+)phosphors have great performance for application in WLEDs and anti-counterfeit inks.展开更多
Er^(3+)-and Tm^(3+)-doped Ca_(x)Sr_(2-x)Nb_(2)O_(7)(C_(x)S_(2-x)N,x=0.6,0.8,1,0,1.2,1,4) phosphors with layered pe rovskite structure were designed.These phosphors exhibit a dominant emission peak at 549 nm under980 n...Er^(3+)-and Tm^(3+)-doped Ca_(x)Sr_(2-x)Nb_(2)O_(7)(C_(x)S_(2-x)N,x=0.6,0.8,1,0,1.2,1,4) phosphors with layered pe rovskite structure were designed.These phosphors exhibit a dominant emission peak at 549 nm under980 nm laser excitation,attributed to the^(4)S_(3/2)→^(4)I_(15/2)transition.By increasing the content of Ca^(2+),the crystal field regulation of rare earth ions is realized and the luminescence enhancement is induced,which is manifested by the increase of^(2)H_(11/2),^(4)S_(3/2)→^(4)I_(15/2)emission.Furthermore,the temperature sensing sensitivities of C_(0.6)S_(1.4)N:Er,Tm and C_(0.6)S_(1.4)N:Er,Tm based on non-thermally coupled energy levels were studied.Finally,an anti-counterfeiting imprint was prepared using phosphors,which have high brightness and excellent photothermal stability.This work not only confirms that closer ionic radii substitution enables to increase the electronic density of states,improve the crystal field symmetry and enhance the luminescence,but also provides a promising phosphor system for temperature sensing and anti-counterfeiting applications,opening up new prospects in the optimization of the optical properties of phosphors.展开更多
A benzoic acid rare earth(Tb) complex was synthesized and characterized.The excitation and emission spectra of the complex were investigated,and then pure organic complex was incorporated with inorganic matrices(SiO2)...A benzoic acid rare earth(Tb) complex was synthesized and characterized.The excitation and emission spectra of the complex were investigated,and then pure organic complex was incorporated with inorganic matrices(SiO2) through sol-gel method.The composition and structure of the hybrid complex was characterized through the IR spectra,TG,TEM and fluorescent spectrometer.Furthermore,the polypropylene(PP) fluorescent fiber with the organic-inorganic hybrid was prepared by melt spinning.The fluorescent and mechanical properties of the fiber were also tested.The results showed that after sol-gel coating the average particulate dimension of the hybrid rare earth complex was less than 100 nm and thermal stability was improved.Meanwhile,the fiber possessed excellent fluorescent and mechanical properties,which could be used as a candidate applied to excellent fluorescent anti-counterfeiting fiber.展开更多
In this study,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals were synthesized controllably,and upconversion luminescence excited at 940 nm and its application in temperature-responsive anti-counterfeitin...In this study,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals were synthesized controllably,and upconversion luminescence excited at 940 nm and its application in temperature-responsive anti-counterfeiting are reported.It is clarified that the Ln^(3+)(Ln=Y+Yb+Ho+Ce)density ratio of bottom plane to side plane in the unit cell can be regulated by Ce^(3+) doping.It is also proved that the energy transfer of Yb^(3+) to Ho^(3+) is responsible for the activation of Ho^(3+)under 940 nm excitation,while the cross relaxation between Ho^(3+)and Ce^(3+)participates in the redistribution of electron population of^(5)S_(2)/^(5)F_(4)and^(5)F_(5)levels.Both theory and experiment confirm that the intensity ratio of red to green emission(I_(R)/I_(G))as a function of temperature as an independent variable has good linear characteristics in the temperature range of 300-500 K.Due to the good responsiveness of multicolor luminescence to temperature,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) with tunable morphology is a promising candidate for advanced temperature-responsive upconversion anti-counterfeiting.Our results provide a new pathway for the controllable synthesis of hexagonal NaYF_(4)microcrystals as well as the regulation of upconversion luminescence that is excited by wavelengths other than 980 nm and its application in anti-counterfeiting.展开更多
Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. ...Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. N-Allylquinolinium bromide under 365 nm UV exhibited intense green RTP emission with response upon adding chloroform. This interesting phenomenon endowed N-allylquinolinium bromide great potential as an anti-counterfeiting material.展开更多
Carbon dots(CDs) with fluorescence(FL) and room-temperature phosphorescence(RTP) optical properties have attracted dramatically growing interest in anti-counterfeiting application. Herein, color-tunable and stable FL ...Carbon dots(CDs) with fluorescence(FL) and room-temperature phosphorescence(RTP) optical properties have attracted dramatically growing interest in anti-counterfeiting application. Herein, color-tunable and stable FL and ultralong RTP(to naked eyes ~14 s) are successfully achieved in CDs system. Encoding information and patterns fabricated by directly screen-printing method are invisible to eyes under natural light. Interestingly, clear and multicolor patterns with tunable FL and RTP emissions are identified under the 365 nm, 395 nm and 465 nm excitation and removal of them, indicating potential application of carbon dots with different FL and RTP outputs in the high-level photonic anti-counterfeiting field.展开更多
Anti-counterfeiting labels with various fluorescent colors are of great importance in information encryption-decryption,but are still limited to static information display.Therefore,it is urgent to develop new materia...Anti-counterfeiting labels with various fluorescent colors are of great importance in information encryption-decryption,but are still limited to static information display.Therefore,it is urgent to develop new materials and encryption-decryption logic for improving the security level of secret information.In this study,an organohydrogel made up of poly(N,N-dimethylacrylamide)(pDMA)hydrogel network and polyoctadecyl methacrylate(pSMA)organogel network that copolymerized with two fluorophores,6-acrylamidopicolinic acid moieties(6APA,fluorescent ligand)and spiropyran units(SPMA,photochromic monomer),was prepared by a two-step interpenetrating method.As UV light of 365nm and 254nm can both cleave C_(spiro)-O bonds of SPMA,and the green fluorescence of 6APA-Tb^(3+) can only be excited by 254nm light,the organohydrogel displays yellow and red under the irradiation of 254nm and 365 nm,respectively.In addition to wavelength selectivity,these two fluorophores are thermal-responsive,leading to the fluorescence variation of the organohydrogel during heating process.As a result,secret information loaded on the organohydrogel can be decrypted by the irradiation of UV light,and the authenticity of the information can be further identified by thermal stimulation.Our fluorescent organohydrogel can act as an effective anti-counterfeiting label to improve the information security and protect the information from being cracked.展开更多
The development of solid-state smart materials, in particular those showing photoresponsive luminescence, is highly desirable for their cutting edge applications in displays, sensors, data-storage, and anticounterfeit...The development of solid-state smart materials, in particular those showing photoresponsive luminescence, is highly desirable for their cutting edge applications in displays, sensors, data-storage, and anticounterfeiting. However, to achieve both excellent photoresponsive performance and bright luminescence in solid state remains challenge. Herein, we integrate a novel photochromic fluorophore YL into flexible polymer chains, thereby enabling the resultant polymer PYL with reversible photoisomerization upon aggregation. Remarkably, the polymer PYL possesses excellent photochromic properties and aggregationinduced emission(AIE) activity, which can be attributed to the photoactive YL moiety. Upon light exposure, its film exhibits reversibly off-to-on fluorescent modulation with quick response, high emission efficiency and signal contrast, sharply different from the weak emission in solution. The novel photoresponsive AIE polymer with invisible/visible color and fluorescence transformation allows for advanced anti-counterfeiting applications. This work provides an efficient platform for constructing solid-state photocontrollable luminescent materials.展开更多
Recently,the ultraviolet(UV)persistent luminescence material(PLM)has attracted extensive attention.However,the design and development of new UV PLM and exploring their promising advanced application remain challenges....Recently,the ultraviolet(UV)persistent luminescence material(PLM)has attracted extensive attention.However,the design and development of new UV PLM and exploring their promising advanced application remain challenges.Here,we developed a new dopant-free self-activated UVA PLM,Zn_(2)Al_(2)SiO_(7),which could be applied in anti-counterfeiting field.Zn_(2)Al_(2)SiO_(7)shows UVA persistent luminescence(PersL)peaking at 380 nm after 254 nm UV lamp excitation.Addition of Yb^(3+),the UVA PersL intensity and time are raised obviously,and the UVA PersL time lasts more than 24 h.In addition,Yb^(3+)-doped Zn_(2)Al_(2)SiO_(7)exhibits photostimulated properties with different light source.Finally,we design anticounterfeiting pattern based on intensity and time resolution from PersL of Zn_(2)Al_(2)SiO_(7),showing its advantages in the anti-counterfeiting field.展开更多
Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we f...Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.展开更多
Counterfeiting is one of the most serious problems in the consumer market. One promising approach for anti-counterfeiting is to attach a low-cost Radio-frequency Identification (RFID) tag to the product authentication...Counterfeiting is one of the most serious problems in the consumer market. One promising approach for anti-counterfeiting is to attach a low-cost Radio-frequency Identification (RFID) tag to the product authentication. In this paper, we propose an RFID system for detecting counterfeiting products. This RFID system consists of the tag authentication protocol and the database correction protocol. We use the tag authentication protocol for authenticating tags without revealing their sensitive information. This protocol also allows the customer to freely inquire the tag. To prevent the widespread of the counterfeit products, we use the tag status information along with tag identity information. Meanwhile, the database correction protocol guarantees the correctness of the tag status. Our anti-counterfeiting system is the first work considering the seller who plays an important role in the consumer product supply chain. Finally, we show that anti-counterfeiting system is quite secure against counterfeiting and the tag authentication protocol is lightweight enough to be implemented in RFID-based applications.展开更多
The developme nt of high-level an ti-co un terfeiti ng tech niq ues is of great sig nifica nee in econo mics and security issues.However,i ntricate read ing methods are required to obta in multi-level info rmati on st...The developme nt of high-level an ti-co un terfeiti ng tech niq ues is of great sig nifica nee in econo mics and security issues.However,i ntricate read ing methods are required to obta in multi-level info rmati on stored in differe nt colors,which greatly limits the applicati on of an ti-co un terfeit ing tech no logy on sol ving real world problems.Here in,we realize multicolor information anti-counterfeiting under simply external stimulation by utilizing the functional groups and multiple emission centers of lanthanide metal organic framework(Ln-MOFs)to tune luminescence color.Water responsive multicolor luminescence represented by both the tunable color from red to blue within the visible region and high sensitive responsivity has bee n achieved,owing to the in creased nonr adiative decay pathways and enhan ced Eu3+-to-liga nd en ergy back tra nsfer.Remarkably,i nfo rmatio n hidde n in differe nt colors n eeds to be read with a specific water content,which can be used as an en crypti on key to en sure the security of the info rmati on for high-level an ti-co un terfeiti ng.展开更多
With the rapid development of science and technology,the high-security-level anti-counterfeiting technique is essential for ensuring property or information security.In this work,we prepared micron NaYTiO_(4):Bi/Er(NY...With the rapid development of science and technology,the high-security-level anti-counterfeiting technique is essential for ensuring property or information security.In this work,we prepared micron NaYTiO_(4):Bi/Er(NYT:Bi/Er) phosphors with integrating up-conversion(UC) photoluminescence,downshifting(DS) emission,phosphorescence and photochromism(PC) performances for advanced multiple anti-counterfeiting application.Owing to the abundant energy levels of Er^(3+)ions,the UC and DS luminescence behaviors are anticipated.Specifically,the yellow-green emission of Er^(3+)ions can be observed upon 980 nm excitation,and the bright green emission is demonstrated under 281 or 254 nm excitation due to the energy transitions of Er^(3+)ions and the energy transfer process from Bi^(3+)to Er^(3+)ions.Besides,the introduction of Bi^(3+)ions generates defect levels in the matrix and thus leads to phosphorescence.Furthermore,the repeatable PC performance could be triggered by the 365 nm irradiation and vanished with 450 nm illumination or thermal stimulation.To verify the practical usability of NYT:Bi/Er phosphors on anti-counterfeiting applications,some experiments are designed and successfully executed.It is believed that the NYT:Bi/Er phosphors can be a promising candidate for high-security-level multiple anti-counterfeiting.展开更多
基金support of the National Natural Science Foundation of China(No.22361011)Guizhou Provincial Science and Technology Projects(No.ZK[2023]General 040)the Guizhou Provincial Key Laboratory Platform Project(No.ZSYS[2025]008)。
文摘This investigation focuses on the utilization of cucurbit[6]uril(Q[6])as the host compound for the development of long-lasting afterglow materials.By strategically manipulating the outer surface interactions of Q[6],classical aggregation-caused quenching(ACQ)compounds such as fluorescein sodium(FluNa)and calcein sodium(CalNa)were transformed into afterglow materials with varying colors and durations upon exposure to ultraviolet light.This transformation was facilitated through a host-vip doping method combined with coordination with metal ions.Even at a reduced doping concentration of 5×10^(-5)wt%,the materials exhibit remarkable afterglow properties,lasting up to 2 s,with a phosphorescence lifetime of up to 150 ms.Moreover,by adjusting the concentration of the vip compound,the persistent luminescence color of the materials could be easily transitioned from orange to yellow and subsequently to green.These findings suggest that the developed afterglow materials hold significant potential for multilevel anti-counterfeiting and information encryption applications when exposed to ultraviolet light.The supramolecular assembly strategy,which relies on the outer surface interactions of cucurbit[n]uril,offers a simpler and more efficient approach to crafting multi-color luminescent materials.Additionally,this method opens avenues for enhancing the application potential of aggregation-caused quenching(ACQ)compounds in various technological domains.
基金financially supported by the National Key R&D Program of China(No.2023YFB3812400)the National Natural Science Foundation of China(Nos.52203353 and52433004)。
文摘The development of organic afterglow materials with high environmental stability and multi-mode luminescence remains a significant challenge in luminescent anti-counterfeiting.In this work,an organic luminescent molecule was encapsulated within polyacrylamide microspheres and embedded in a gold nanorod-doped,ferric ion-crosslinked hydrogel exhibiting upper critical solution temperature behavior.The obtained composites exhibited fluorescence,thermally activated delayed fluorescence,and phosphorescence.Through the application of extrusion or uniaxial stretching,the orientation of the gold nanorods was modulated,enabling polarization-dependent luminescence through transverse surface plasmon resonance absorption.At 300%uniaxial strain,the polarized fluorescence intensity difference at 520 nm reached 0.29.Furthermore,ultraviolet irradiation was employed to locally disrupt the orientation of the gold nanorods,resulting in depolarization within the irradiated regions.These areas displayed non-polarized fluorescence,while the non-irradiated regions retained both emission and fluorescence polarization characteristics.Localized imprinting was employed to modulate material thickness,thereby controlling the density of gold nanorods.Thinner regions exhibited weaker transverse localized surface plasmon resonance absorption,while thicker regions showed stronger absorption,enabling the coexistence of blue–green fluorescence and polarization patterns.Local humidification effectively reduced phosphorescence intensity,enhancing the material's environmental responsiveness.The composite demonstrated excellent reversibility over multiple stretching–selfhealing cycles and pattern-switching processes,highlighting its strong potential for multidimensional optical encryption and intelligent anticounterfeiting applications.
基金funded by the National Natural Science Foundation of China(Nos.22101267 and 82103686)the Natural Science Foundation of Henan Province(202300410477 and 24230042123)the China Postdoctoral Science Foundation(Nos.2021M692905 and 2024T170832).
文摘The application of aggregation-induced emission(AIE)materials in biological imaging holds multiple significances,including improving detection sensitivity and specificity,optimizing the imaging process,expanding the scope of application,and promoting advancements in biomedical research.In this work,the propeller ligand was constructed through McMurry coupling reaction and Suzuki coupling reaction by using dimethoxybenzophenone as the starting material.Then,an imine condensation reaction was carried out in chloroform solution,using a 3:2 molar ratio of precursor to tri(2-aminoethyl)amine to synthesize C3 symmetric porous organic cage CB.The structures of the compounds were determined by nuclear magnetic resonance spectroscopy(NMR),electrospray ionization mass spectrometry(ESI-MS)and Fourier transform infrared spectroscopy(FT-IR).The optical investigation results reveal that ligand L-B and the porous organic cage C_(B) demonstrate remarkable aggregation-induced emission(AIE)properties in a tetrahydrofuran/water mixed solvent system,along with a pronounced response to tetrahydrofuran vapor stimuli.Consequently,Furthermore,given its unique cage-like structure,high quantum yield,and outstanding AIE behavior,the porous organic cage C_(B) holds promise for applications in cell imaging.
基金the National Natural Science Foundation of China(22171105 and 22471096)Natural Sci-ence Foundation of Shandong Province(ZR2022YQ14,ZR2022QB127 and ZR2022QB221)Special Foundation of Taishan Scholar Project and Young Innovative Team Project for Colleges and Universities of Shandong Province(2024KJH053).
文摘Stimuli-responsive luminescent switching materials with multifunctional properties are highly essential for advanced photonic applications,yet achieving such capabilities in halide perovskites continues to pose a signif-icant challenge.In this work,we explore a new water-stimuli-responsive zero-dimensional(0D)Sb-based halide of[PhPz]_(2)SbCl_(7)·2H_(2)O(PhPz=phenylpiperazine),which consists of isolated[SbCl_(6)]^(3-) octahedra in[PhPz]2+cationic matrix with vip H_(2)O molecules.Under UV excitation,[PhPz]_(2)SbCl_(7)·2H_(2)O emits intense broadband red light with maximum emission at 645 nm,and combined optical characterization and theoretical calculations confirm that this luminescence originates from self-trapped excitons(STEs).Interestingly,the free water molecules can reversibly leave and entry the crystal lattice during heating-cooling cycles accompanied by the formation of dehydrated phase,which displays strong yellow emission with maximum peak at 580 nm.Therefore,reversible luminescent switching between red and yellow emission is achieved through controllable removal and adsorption process of vip H_(2)O.By virtue of this reversible thermochromic switching,this halide can be used to detect the trace amount of water in various organic solvents and humidity of moist air.In addition,such switchable dual emission further realizes application in anti-counterfeiting and information encryption-decryption.This work deepens the understanding of structure-property relationships and expands the application range of oD metal halides.
基金supported by the National Natural Science Foundation of China(Nos.22201057 and 22472044)Zhejiang Provincial Natural Science Foundation of China(Nos.LR22B010001 and LQ23B010001)。
文摘In this work,we synthesize two luminescent Pt(Ⅱ)complexes using differentπ-conjugated bidentate ligands.Both complexes are assembled into three-dimensional(3D)networks through non-classical intermolecular interactions in the crystal state.Unexpectedly,substituting pyridine with the more extensivelyπ-conjugated quinoline significantly increases the dihedral angles between the phenyl and quinolyl groups of the bidentate ligands.This alteration disrupts theπ-πinteractions between molecules,resulting in distinct optical properties upon exposure to external stimuli.By integrating these complexes into polymers,we fabricate electrospun films containing luminescent nanofibers that exhibit reversible optical changes.These findings have paved the way for the development of high-performance optical encryption and anti-counterfeiting materials,achieved through the employment of simple chromophores.
文摘Counterfeiting is still a pervasive global issue,affecting multiple industries and hindering industrial innovation,while causing substantial financial losses,reputational damage,and risks to consumer safety.From luxury goods and pharmaceuticals to electronics and automotive parts,counterfeit products infiltrate supply chains,leading to a loss of revenue for legitimate businesses and undermining consumer trust.Traditional anti-counterfeiting measures,such as holograms,serial numbers,and barcodes,have proven to be insufficient as counterfeiters continuously develop more sophisticated replication techniques.As a result,there is a growing need for more advanced,secure,and reliable methods to prevent counterfeiting.This paper presents a novel,holistic anti-counterfeiting platform that integrates Near Field Communication(NFC)-enabled mobile applications with blockchain technology to provide an innovative,secure,and consumer-friendly authentication mechanism.Our approach addresses key gaps in existing solutions by incorporating dynamic product identifiers,which make replication significantly more difficult.The system enables consumers to verify the authenticity of products instantly using their smartphones,enhancing transparency and trust in the supply chain.Blockchain technology plays a crucial role in our proposed solution by providing an immutable,decentralized ledger that records product authentication data.This ensures that product verification records cannot be tampered with or altered,adding a layer of security that is absent in conventional systems.Additionally,NFC technology enhances security by offering unique identification capabilities,enabling real-time product verification.To validate the effectiveness of the proposed system,real-world testing was conducted across different industries.The results demonstrated the platform’s ability to significantly reduce counterfeit products in the supply chain,offering businesses and consumers a more robust and reliable authentication method.By leveraging the combined strengths of blockchain and NFC,this solution represents a significant advancement in the fight against counterfeiting,ensuring enhanced security,transparency,and consumer trust.
基金supported by Chongqing Natural Science Foundation Innovation and Development Joint Fund(CSTB2025NSCQ-LZX0001)Ongoing Research Funding Program,(ORF-2025-762)King Saud University,Riyadh,Saudi Arabia,National Natural Science Foundationof China(11974063).
文摘Low-dimensional lead-free metal halides have emerged as promising candidates for anti-counterfeiting applications,characterized by their low toxicity,diverse crystal structures,and exceptional optical properties.Conventional anti-counterfeiting technologies based on low-dimensional metal halides are often constrained by complex and time-consuming heating and solvent treatments that may insufficiently modify the luminescent characteristics of emitters,thus hindering their practical implementation in effective anti-counterfeiting strategies.In this study,we employ an innovative alloying strategy in low-dimensional zinc halides Cs_(2)ZnCl_(4) to enhance their luminescent performance.By introducing self-trapped exciton(STE)states through the alloying of Cu^(+)and Sb^(3+)ions in Cs_(2)ZnCl_(4),we achieve bright blue and red photoluminescence(PL)centered at 492 nm and 744 nm,respectively,under 266 nm excitation,with only red emission observed under 365 nm excitation.This approach enables instant and reliable anti-counterfeiting applications.This work presents new opportunities for developing robust anti-counterfeiting and information encryption/decryption technologies.
基金supported by Guizhou Provincial Basic Research Program(Natural Science)(Qian ke he ji chu-ZK2024 YiBan 095)。
文摘In this study,a novel Ca_(2)GaTaO_(6):Sm^(3+)phosphor was developed using the conventional hightemperature solid-phase method.The phase structure and morphology test results of phosphor indicate that the Ca_(2)GaTaO_(6):Sm^(3+)material was successfully synthesized and the Sm^(3+)ions were successfully doped into the host lattice.When utilizing 406 nm excitation,the Ca_(2)GaTaO_(6):Sm^(3+)phosphor has the strongest emission intensity at 599 nm and shows orange-red emission,which is mainly owing to the^(4)G_(5/2)→^(6)H_(7/2)jump of Sm^(3+)ions.For the performance of different concentrations of Sm^(3+)ions,3 mol%performs the best.At this time,concentration quenching occurs,which is most predominantly induced by dipole-dipole(d-d)interactions.In terms of thermal stability,the Ca_(2)GaTaO_(6):Sm^(3+)phosphor shows good properties,with the luminescence intensity at 423 K exhibiting 88.17%of that at 298 K.The white light-emitting diodes(WLEDs)devices prepared using Ca_(2)GaTaO_(6):Sm^(3+):0.03Sm^(3+)phosphor shows warm white light with excellent performance in terms of correlated color temperature and color rendering index(CCT=3642 K,CRI,Ra=93.5).In terms of anticounterfeit inks,the Ca_(2)GaTaO_(6):Sm^(3+)phosphor also shows good potential.These research results show that Ca_(2)GaTaO_(6):Sm^(3+)phosphors have great performance for application in WLEDs and anti-counterfeit inks.
基金Project supported by the Science and Technology International Cooperation Project of Qinghai Province (2022-HZ-807)the Open Project Salt Lake Chemical Engineering Research Complex,Qinghai University (2023-DXSSZZ-04)。
文摘Er^(3+)-and Tm^(3+)-doped Ca_(x)Sr_(2-x)Nb_(2)O_(7)(C_(x)S_(2-x)N,x=0.6,0.8,1,0,1.2,1,4) phosphors with layered pe rovskite structure were designed.These phosphors exhibit a dominant emission peak at 549 nm under980 nm laser excitation,attributed to the^(4)S_(3/2)→^(4)I_(15/2)transition.By increasing the content of Ca^(2+),the crystal field regulation of rare earth ions is realized and the luminescence enhancement is induced,which is manifested by the increase of^(2)H_(11/2),^(4)S_(3/2)→^(4)I_(15/2)emission.Furthermore,the temperature sensing sensitivities of C_(0.6)S_(1.4)N:Er,Tm and C_(0.6)S_(1.4)N:Er,Tm based on non-thermally coupled energy levels were studied.Finally,an anti-counterfeiting imprint was prepared using phosphors,which have high brightness and excellent photothermal stability.This work not only confirms that closer ionic radii substitution enables to increase the electronic density of states,improve the crystal field symmetry and enhance the luminescence,but also provides a promising phosphor system for temperature sensing and anti-counterfeiting applications,opening up new prospects in the optimization of the optical properties of phosphors.
基金Project supported by the Chinese Ministry of Education (208005)Young Scientist Backbone of Heilongjiang Common Higher University (1154G03)
文摘A benzoic acid rare earth(Tb) complex was synthesized and characterized.The excitation and emission spectra of the complex were investigated,and then pure organic complex was incorporated with inorganic matrices(SiO2) through sol-gel method.The composition and structure of the hybrid complex was characterized through the IR spectra,TG,TEM and fluorescent spectrometer.Furthermore,the polypropylene(PP) fluorescent fiber with the organic-inorganic hybrid was prepared by melt spinning.The fluorescent and mechanical properties of the fiber were also tested.The results showed that after sol-gel coating the average particulate dimension of the hybrid rare earth complex was less than 100 nm and thermal stability was improved.Meanwhile,the fiber possessed excellent fluorescent and mechanical properties,which could be used as a candidate applied to excellent fluorescent anti-counterfeiting fiber.
基金Project supported by the National Natural Science Foundation of China(11575059)Natural Science Foundation of Huzhou City(2018YZ08)。
文摘In this study,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals were synthesized controllably,and upconversion luminescence excited at 940 nm and its application in temperature-responsive anti-counterfeiting are reported.It is clarified that the Ln^(3+)(Ln=Y+Yb+Ho+Ce)density ratio of bottom plane to side plane in the unit cell can be regulated by Ce^(3+) doping.It is also proved that the energy transfer of Yb^(3+) to Ho^(3+) is responsible for the activation of Ho^(3+)under 940 nm excitation,while the cross relaxation between Ho^(3+)and Ce^(3+)participates in the redistribution of electron population of^(5)S_(2)/^(5)F_(4)and^(5)F_(5)levels.Both theory and experiment confirm that the intensity ratio of red to green emission(I_(R)/I_(G))as a function of temperature as an independent variable has good linear characteristics in the temperature range of 300-500 K.Due to the good responsiveness of multicolor luminescence to temperature,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) with tunable morphology is a promising candidate for advanced temperature-responsive upconversion anti-counterfeiting.Our results provide a new pathway for the controllable synthesis of hexagonal NaYF_(4)microcrystals as well as the regulation of upconversion luminescence that is excited by wavelengths other than 980 nm and its application in anti-counterfeiting.
基金the financial support from the Instrument Developing Project of the Chinese Academy of Sciences (No. YJKYYQ20170009)the National Natural Science Foundation of China(NSFC Nos. 21722603 and 21871083)the Innovation Program of Shanghai Municipal Education Commission
文摘Pure organic room-temperature phosphorescence (RTP) materials have been attracting much attention recently. Herein, we report a facile approach combining heavy atom effect and external solvent stimuli to realize RTP. N-Allylquinolinium bromide under 365 nm UV exhibited intense green RTP emission with response upon adding chloroform. This interesting phenomenon endowed N-allylquinolinium bromide great potential as an anti-counterfeiting material.
基金supported by the Natural Science Foundation of Hubei Province for Distinguished Young Scholars (No. 2019CFA056)the Fundamental Research Funds for the Central Universities and Wuhan University and the Fundamental Research Funds for the Central Universities (No. 2042021kf0226)。
文摘Carbon dots(CDs) with fluorescence(FL) and room-temperature phosphorescence(RTP) optical properties have attracted dramatically growing interest in anti-counterfeiting application. Herein, color-tunable and stable FL and ultralong RTP(to naked eyes ~14 s) are successfully achieved in CDs system. Encoding information and patterns fabricated by directly screen-printing method are invisible to eyes under natural light. Interestingly, clear and multicolor patterns with tunable FL and RTP emissions are identified under the 365 nm, 395 nm and 465 nm excitation and removal of them, indicating potential application of carbon dots with different FL and RTP outputs in the high-level photonic anti-counterfeiting field.
基金supported by the National Key R&D Program of China(No.2022YFB3204300)the National Natural Science Foundation of China(No.52103246)+1 种基金Zhejiang Provincial Natural Science Foundation,China(No.LQ22E030015)Natural Science Foundation of Ningbo,China(No.20221JCGY010301).
文摘Anti-counterfeiting labels with various fluorescent colors are of great importance in information encryption-decryption,but are still limited to static information display.Therefore,it is urgent to develop new materials and encryption-decryption logic for improving the security level of secret information.In this study,an organohydrogel made up of poly(N,N-dimethylacrylamide)(pDMA)hydrogel network and polyoctadecyl methacrylate(pSMA)organogel network that copolymerized with two fluorophores,6-acrylamidopicolinic acid moieties(6APA,fluorescent ligand)and spiropyran units(SPMA,photochromic monomer),was prepared by a two-step interpenetrating method.As UV light of 365nm and 254nm can both cleave C_(spiro)-O bonds of SPMA,and the green fluorescence of 6APA-Tb^(3+) can only be excited by 254nm light,the organohydrogel displays yellow and red under the irradiation of 254nm and 365 nm,respectively.In addition to wavelength selectivity,these two fluorophores are thermal-responsive,leading to the fluorescence variation of the organohydrogel during heating process.As a result,secret information loaded on the organohydrogel can be decrypted by the irradiation of UV light,and the authenticity of the information can be further identified by thermal stimulation.Our fluorescent organohydrogel can act as an effective anti-counterfeiting label to improve the information security and protect the information from being cracked.
基金financially supported by the National Natural Science Foundation of China for Science Center Program (No. 21788102)Creative Research Groups (No. 21421004)+4 种基金Key Project (No. 21636002)Shanghai Pujiang Program (No. 20PJ1402900)National key Research and Development Program (No. 2016YFA0200300)Shanghai Municipal Science and Technology Major Project (No. 2018SHZDZX03)Program of Introducing Talents of Discipline to Universities (No. B16017)。
文摘The development of solid-state smart materials, in particular those showing photoresponsive luminescence, is highly desirable for their cutting edge applications in displays, sensors, data-storage, and anticounterfeiting. However, to achieve both excellent photoresponsive performance and bright luminescence in solid state remains challenge. Herein, we integrate a novel photochromic fluorophore YL into flexible polymer chains, thereby enabling the resultant polymer PYL with reversible photoisomerization upon aggregation. Remarkably, the polymer PYL possesses excellent photochromic properties and aggregationinduced emission(AIE) activity, which can be attributed to the photoactive YL moiety. Upon light exposure, its film exhibits reversibly off-to-on fluorescent modulation with quick response, high emission efficiency and signal contrast, sharply different from the weak emission in solution. The novel photoresponsive AIE polymer with invisible/visible color and fluorescence transformation allows for advanced anti-counterfeiting applications. This work provides an efficient platform for constructing solid-state photocontrollable luminescent materials.
基金Project supported by the National Natural Science Foundation of China(61705228,62105333,11864015)the Natural Science Foundation of Fujian Province,China(2019J05159)。
文摘Recently,the ultraviolet(UV)persistent luminescence material(PLM)has attracted extensive attention.However,the design and development of new UV PLM and exploring their promising advanced application remain challenges.Here,we developed a new dopant-free self-activated UVA PLM,Zn_(2)Al_(2)SiO_(7),which could be applied in anti-counterfeiting field.Zn_(2)Al_(2)SiO_(7)shows UVA persistent luminescence(PersL)peaking at 380 nm after 254 nm UV lamp excitation.Addition of Yb^(3+),the UVA PersL intensity and time are raised obviously,and the UVA PersL time lasts more than 24 h.In addition,Yb^(3+)-doped Zn_(2)Al_(2)SiO_(7)exhibits photostimulated properties with different light source.Finally,we design anticounterfeiting pattern based on intensity and time resolution from PersL of Zn_(2)Al_(2)SiO_(7),showing its advantages in the anti-counterfeiting field.
基金supported by the National Natural Science Foundation of China(Nos.52370110 and 21607044)supported by the Fundamental Research Funds for the Central Universities(No.2023MS146)the Open Research Fund of the School of Chemistry and Chemical Engineering,Henan Normal University for support(Nos.2020ZD01 and 2021YB07)。
文摘Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.
文摘Counterfeiting is one of the most serious problems in the consumer market. One promising approach for anti-counterfeiting is to attach a low-cost Radio-frequency Identification (RFID) tag to the product authentication. In this paper, we propose an RFID system for detecting counterfeiting products. This RFID system consists of the tag authentication protocol and the database correction protocol. We use the tag authentication protocol for authenticating tags without revealing their sensitive information. This protocol also allows the customer to freely inquire the tag. To prevent the widespread of the counterfeit products, we use the tag status information along with tag identity information. Meanwhile, the database correction protocol guarantees the correctness of the tag status. Our anti-counterfeiting system is the first work considering the seller who plays an important role in the consumer product supply chain. Finally, we show that anti-counterfeiting system is quite secure against counterfeiting and the tag authentication protocol is lightweight enough to be implemented in RFID-based applications.
基金This work was supported by the National Natural Science Foundation of China(Nos.52025131,51632008,51772268,and 61721005)Zhejiang Provincial Natural Science Foundation of China(No.LD18E020001).
文摘The developme nt of high-level an ti-co un terfeiti ng tech niq ues is of great sig nifica nee in econo mics and security issues.However,i ntricate read ing methods are required to obta in multi-level info rmati on stored in differe nt colors,which greatly limits the applicati on of an ti-co un terfeit ing tech no logy on sol ving real world problems.Here in,we realize multicolor information anti-counterfeiting under simply external stimulation by utilizing the functional groups and multiple emission centers of lanthanide metal organic framework(Ln-MOFs)to tune luminescence color.Water responsive multicolor luminescence represented by both the tunable color from red to blue within the visible region and high sensitive responsivity has bee n achieved,owing to the in creased nonr adiative decay pathways and enhan ced Eu3+-to-liga nd en ergy back tra nsfer.Remarkably,i nfo rmatio n hidde n in differe nt colors n eeds to be read with a specific water content,which can be used as an en crypti on key to en sure the security of the info rmati on for high-level an ti-co un terfeiti ng.
基金supported by the Introduced Innovative R&D Team Project of "The Pearl River Talent Recruitment Program"of Guangdong Province (No.2019ZT08C321)Guangdong Basic and Applied Basic Research Foundation (No.2019A1515110443)the National Natural Science Foundation of China (No.51872327)。
文摘With the rapid development of science and technology,the high-security-level anti-counterfeiting technique is essential for ensuring property or information security.In this work,we prepared micron NaYTiO_(4):Bi/Er(NYT:Bi/Er) phosphors with integrating up-conversion(UC) photoluminescence,downshifting(DS) emission,phosphorescence and photochromism(PC) performances for advanced multiple anti-counterfeiting application.Owing to the abundant energy levels of Er^(3+)ions,the UC and DS luminescence behaviors are anticipated.Specifically,the yellow-green emission of Er^(3+)ions can be observed upon 980 nm excitation,and the bright green emission is demonstrated under 281 or 254 nm excitation due to the energy transitions of Er^(3+)ions and the energy transfer process from Bi^(3+)to Er^(3+)ions.Besides,the introduction of Bi^(3+)ions generates defect levels in the matrix and thus leads to phosphorescence.Furthermore,the repeatable PC performance could be triggered by the 365 nm irradiation and vanished with 450 nm illumination or thermal stimulation.To verify the practical usability of NYT:Bi/Er phosphors on anti-counterfeiting applications,some experiments are designed and successfully executed.It is believed that the NYT:Bi/Er phosphors can be a promising candidate for high-security-level multiple anti-counterfeiting.
