The Research On Luminescent Properties Of Rare Earth Doped Stannate

The special crystal structure of Ca2SnO4 is favorable for other ions to enter the lattice easily,and generate suitable trap to store the excitation energy,?SnO4?4-is suitable for matrix materials because of its optical inertia.Ca2SnO4: Eu³⁺ phosphors are a very important kind of red light-emitting material,which can produce better luminescence and afterglow under UV excitation.The materials has good thermal stability,high chemical stability,high color purity,safety,environmental protection,no radiation and crystal structure stability,and it has a good application prospect in so many fields,such as display,optical fiber communication,biosensor and so on.So it is very important for us to study the Ca2SnO4: Eu³⁺ phosphors.The phosphors which in the paper were prepared by solid-state reaction and all the research based on Ca2SnO4: Eu³⁺,and the about experimental phenomena and conclusions in the paper were analyzed very carefully by us.The Ca_1.99SnO₄: 0.01Eu³⁺ phosphors and Ca0.99SnO3: 0.01Eu³⁺ phosphors are at different sintering temperature and time were prepared.According to the XRD and spectra,we know that CaSnO3 is easier to obtain and has strong thermal stability,the parameter about optimumpreparation of Ca2SnO4: Eu³⁺phosphors is 1350 oC,4h.No matter pre sintering or not,there is no effect on matrix's crystal structure and emission intensity of Ca_2-xSnO)4: xEu³⁺?x=0?0.001?0.005?0.01?0.015?0.02?.There is a charge transfer band of Eu³⁺-O2-in the samples' excitation spectrum,which band is at200²95nm;with the increasing of Eu³⁺concentration,the peak position of charge transfer band showa red shift.The mainly emission of Eu³⁺ ion is transition of5D0—7F2.The luminescence intensity strengthen with increasing Eu³⁺-doped concentration,the two peaks at 614 nm and 618 nm become one emission peak located at 616 nm gradually at the same time.The emission intensity of Ca_2-xSnO)4:xEu³⁺sintered in vacuum atmosphere is about twice as much as that in air,the oxygenvacancies increase because of the vacuum atmosphere,which leads to the increase of electron traps,and then the afterglow properties of samples have been improved greatly.According to the XRD and spectra of Ca1.96SnO4: 0.02Eu³⁺,0.02A+?A=Li?Na?K?and Ca1.98-y SnO4: 0.02Eu³⁺,yGd³⁺?y=0?0.01?0.02?0.04?0.08?0.12?,we can see that there is no effect on matrix's crystal structure and the spectral shape of Ca_1.98SnO₄: 0.02Eu³⁺ by doping A+ and Gd³⁺ ions respectively,but the luminescence intensity of Ca_1.98SnO₄: 0.02Eu³⁺ phosphors is improved obviously.The dope of Gd³⁺ions improves the afterglow property of Ca_1.98SnO₄: 0.02Eu³⁺ phosphors,the afterglow intensity increases at first and then decreases with the increasing of Gd³⁺-doped concentration,when the doping concentration is 0.02 mol,the afterglow property is the best.