Preparation And Photoluminescence Properties Of Rare Earth Doped Sodium Potassium Niobate Nanofibers

Rare earth luminescent materials have been widely used in lighting,display,optical storage,medical radiation and other fields due to their special structure,strong light absorption,high conversion efficiency,and stable physical and chemical properties.Nanomaterials have special size effects,surface effects and tunneling effects,and exhibit excellent performance in the fields of light,sound,magnetism and electricity.The development of nanotechnology can bring new vitality to the research of rare earth luminescent materials and expand its application fields.Therefore,through the combination of rare earth luminescent materials and nanotechnology,nano-scale rare earth luminescent materials with photoelectric properties can be prepared.In this paper,the perovskite solid solution(Na_0.5K_0.5)NbO₃ was used as the matrix,the precursor solution was prepared by sol-gel technique,and the one-dimensional nanomaterial was prepared by the electrospinning method.Eu-doped(K_0.5Na_0.5)_1-xEu_xNbO₃ fibers were fabricated,and sintered at different temperatures?500?,600?,700?,800?,900??.The samples exhibited strong red emission at the sintering treatment of 700?.The nanofiber of Er-doped(K_0.5Na_0.5)_1-xEr_xNbO₃ was prepared,and the luminescent properties of the fiber can be explored by controlling the concentration of Er ions.The excitation wavelength of 980 nm was used to excite the sample,and the three luminescence peaks were located at 528 nm,551 nm and 662 nm.The luminescence performance of the sample was optimal for x=0.015.Through the relationship between pump power and upconversion luminescence intensity,it is proved that the two-photon absorption is involved in the green emission,and the two-photon or three-photon absorption process is involved in the red emission.The nanofibers and particles of Pr-doped(K_0.5Na_0.5)_1-xPr_xNbO₃ materials were fabricated.Firstly,the prepared colloid is divided into two parts,one part is manufactured into fiber,the other part is placed in an oven for drying at 80?.Finally,two different samples were obtained by sintering at 700?The fiber or particle samples exhibited a single phase perovskite structure,and the emission peak position and spectral width of the two materials are unchanged.However,the quenching concentrations of the two materials are different.For the fiber sample of x=0.005,the luminescence performance is optimal,and when the powder sample is x=0.003,the luminescence performance is optimal.For Pr and Er co-doped(K_0.5Na_0.5)_0.99-xPr_0.01Er_xNbO₃ nanofibers,the emission spectra showed green and red emission at 548 nm and 606 nm,respectively.The sintered fiber has a diameter of about 200 nm,and the fiber diameter can be controlled by changing the electrospinning voltage.By controlling the excitation wavelength and the Er ion doping concentration,a transition from red light to green light can be achieved.