| With the advent of the era of big data,the demand for data storage is also growing.There are many forms of data storage,among which optical data storage has its unique advantages.It is a simple and effective method to store optical data using long-lasting phosphors.Long persistent luminescence is a unique optical phenomenon.When excited by high-energy radiation(visible light,ultraviolet,X-ray or gamma rays),phosphorescent materials can emit ultraviolet,visible or infrared light for a time ranging from seconds,minutes to hours.This special light-emitting material was first used for low-light illumination,night vision equipment,and later for radioactivity detection and internal biological imaging.Now,more and more researchers have applied it to optical information storage and optical information anti-counterfeiting.In this paper,the new type of long persistent luminescence nanoparticles were explored and optimized through material screening,material synthesis,persistent luminescence performance characterization and other aspects,and some kinds of fluoride nanoparticles with excellent long persistent luminescence performance were found out which could be applied in the field of optical information storage,and the internal persistent luminescence mechanism of the material was analyzed through calculation.Finally,the long persistent luminescence nanoparticle ink was prepared,and the high-throughput optical information storage with larger data storage capacity was realized by using inkjet printing technology.The specific research results of this paper are as follows:(1)When selecting materials suitable for high-temperature optical information storage,it was found that the thermoluminescence peak temperature of NaMgF3:Tb3+nanoparticles was around 420 K after being irradiated by X-ray at room temperature,which could be perfectly applied to optical information storage.In addition,the nanoparticles have excellent optical storage capability and can emit long green persistent luminescence under controlled thermal stimulation.(2)In order to explore the persistent luminescence mechanism of long persistent luminescence nanoparticles,the HRBE energy level diagram was established and the internal electron transition process was elucidated.According to Hoogenstraaten method,the excited state Tb2+energy level of CaF2:Tb3+nanoparticles is about 0.77 eV.The excited Tb2+energy level of NaMgF3:Tb3+nanoparticles is about 1.27 eV,which is close to the trap depth of 0.71 eV and 1.08 eV,respectively,characterized by thermoluminescence.Therefore,it is speculated that in the process of X-ray irradiation of CaF2:Tb3+and NaMgF3:Tb3+nanoparticles,Tb3+ions act as both luminescence center and trap center in the matrix material.(3)In the experiment of the optimization of the persistent luminescence property of NaMgF3:Tb3+,the inert shell of NaMgF3 was coated on the surface of the first synthesized NaMgF3:Tb3+nanoparticles by using the surface passivation strategy,and it was found that the persistent luminescence property of the material changed with the thickness of the shell layer.The experimental results show that when the core-shell ratio is 10:1,the persistent luminescence performance of nanoparticles is improved most obviously.The results indicate that the inert coating can effectively inhibit the energy quenching of the luminous center on the particle surface and improve the long persistent luminescence performance of the material.(4)NaMgF3:Tb3+@NaMgF3 nanoparticles have good dispersion and stability in water.In this experiment,long persistent luminescence nanoparticles ink was successfully prepared,and its application in optical information storage and anti-counterfeiting of optical information was realized through inkjet printing technology.It can be seen from the photos taken that NaMgF3:Tb3+@NaMgF3 nanoparticles have great application prospects in optical information storage and optical information anti-counterfeiting,which provides new opportunities for the next generation of information storage and biomedical technology. |
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