Adjustment And Control Of Cu,Ag Particles To Photoluminescence Characteristics Of CaSrSiO₄:Tb³⁺/Yb³⁺,Er³⁺ Phosphor

With a large number of advantages such as high luminescence productivity,excellent color purity and stable property,the nanophosphor doped with rare earth elements has been applied into many optical fields,including Laser diode,optical amplifier,LED lighting and sensors.It is of great scientific significance and potential application to improve the luminescence property and analysis the photoluminescence mechanism.In this paper,the photoluminescence productivity of Tb³⁺-doped and Yb³⁺:Er³⁺co-doped CaSrSiO₄nanophosphor is improved by the LSPR of copper and silver nanoparticles.The main work is as follows:Firstly,a series of CaSrSiO₄:Tb³⁺nanophosphors doped with copper nanoparticles were prepared by high temperature solid state reaction.The crystal structure and morphology of some samples were characterized and analyzed by XRD and SEM.It is found that the doping of copper nanoparticles has no obvious influence on the crystal structure of CaSrSiO₄:Tb³⁺nanophosphor.The main diffraction peak is still consistent with the standard CaSrSiO₄ crystal card,indicating that the corporation of copper nanoparticles has no effect on the microstructure of CaSrSiO₄:Tb³⁺nanophosphor.However,the SEM images show that the size of nanophosphor particle becomes bigger with the increase of the concentration of doped copper nanoparticles.when the concentration of copper increased from 0.1 to 0.7 mol%,the average size of CaSrSiO₄:Tb³⁺,Cu phosphor particle changed from 60 to 150 nm.In addition,the excitation and emission spectra of Tb³⁺and Copper co-doped CaSrSiO₄nanophosphor were measured.Under 245 nm ultra-violet excitation,it was found that there were six distinct peaks belongs to Tb³⁺in the nanophosphor,of which the central wavelength was 380,415,437,544,585 and 624 nm,and the strongest peak was the green emission of 544nm.The optimized concentration of Tb³⁺is 0.7 mol%.In particular,the photoluminescence properties of CaSrSiO₄:Tb³⁺nanophosphor can be controlled by changing the doping concentration of copper nanoparticles.When the doping concentration of copper nanoparticles is 0.3 mol%,the photoluminescence intensity of CaSrSi O₄:Tb³⁺phosphor can be significantly improved.Finally,combinig the emission spectrum of CaSrSiO₄:Cu poewder and TEM photograph of CaSrSiO₄:Tb³⁺,Cu phosphor particle,the essential mechanism of the influence of copper nanoparticles on the photoluminescence properties of CaSrSiO₄:Tb³⁺nanophosphors is preliminarily analyzed.Secondly,a series of CaSrSiO₄:Yb³⁺,Er³⁺nanophosphors doped with silver nanoparticles were prepared by high temperature solid state reaction,similarly.The results of XRD and SEM show that the doping of silver nanoparticles has no obvious effect on the crystal structure and morphology of CaSrSi O₄:Yb³⁺,Er³⁺nanophosphor.Under the pumping of 980 nm semiconductor laser,the upconversion photoluminescence spectra of CaSrSiO₄:Yb³⁺,Er³⁺,Ag phosphor were measured,and the spectra shows strong green light emission at 545 and 521nm,weak red light emission at 660 nm and blue light emission at 490 nm.Similarly,the photoluminescence intensity of CaSrSiO₄:Yb³⁺,Er³⁺nanophosphor can be obviously regulated with the change of silver doping concentration.For the CaSrSiO₄ nanophosphor doped with different Yb³⁺and Er³⁺doping concentration ratio of 17:1 and 9:1,the photoluminescence intensity of several main emission peaks of the CaSrSiO₄:Yb³⁺,Er³⁺nanophosphors were significantly enhanced when doping with 0.1 and0.5 mol%silver nanoparticles.Indicatingthat when the doping ratio between Yb³⁺and Er³⁺is different,the optimized concentration of silver dopeing concentraton is also different.Meanwhile,the power spectrum of CaSrSiO₄:Yb³⁺,Er³⁺,Ag phosphor was measured and shows that the upconversion photoluminescence of the phosphor is two photon process.Finally,the intrinsic mechanism about the influence of silver nanoparticles on the photoluminescence properties of CaSrSiO₄:Yb³⁺,Er³⁺phosphors is discussed.