Synthesis And Properties Reasearch Of CaTiO₃:Dy³⁺ White Phosphor

White light emitting diodes（WLED）be considered as the most promising light to achieve Green Light because of its advantages such as high energy conversion efficient and environmental protection.Nowadays,most of WLEDs are based on a combination of yellow phosphor YAG:Ce³⁺and blue light emitting LED chips,or a combination of ultraviolet light（UV）and tri-colored phosphors,that is to say red,green and blue emitting phosphors.However,these two method have their own drawbacks,which significantly affect the practical performance of WLED based on these two methods.On the one hand,achieving WLED via the first method greatly limit the choices of phosphors,because the first method need phosphor could be excited by blue light,meanwhile,the phosphor could emit yellow light.And in practical application,the correlated color temperature of the WLED based on the first method is too high because of the lack of red light,which also limits the area of WLED application.On the other hand,the WLED based on the second way have low luminous efficiency because of the amount of phosphors which used in this method is too many,and it also makes the process flow complicated.For resolving these problem,research and seek a kind of single-phase white emitting phosphors which could be excited by UV light is imperative.Perovskite（CaTiO₃）become a kind of popular matrix utilized in the research of phosphors because of its excellent physicochemical properties and typical crystal structure.In this research,the perovskite-based rare earth doping luminescent materials(CaTi3:Dy³⁺)with Dy³⁺as the main luminescent center ion synthesized by combustion method have been studied.The luminescent properties of CaTiO₃:Dy³⁺have been optimized by doping Mg²⁺,Zn²⁺,Pr³⁺,and alkali metal M⁺（M⁺=Li⁺,Na⁺,K⁺）.CaTiO₃:Dy³⁺white light eimtting phosphor was successfully synthesized by combustion method.Under ultraviolet excitation,the phosphor could emits white light which was combined via two main emission peaks of 484 and 578 nm,respectively.At the same time,the effect of process parameters on the properties of C aTiO₃:Dy³⁺phosphor was investugated.The results showed that CaTiO₃:Dy³⁺phosphor had the best luminescent properties at 900 C,60 minutes holding time and 2%mol of Dy³⁺doping concentration.When the concentration of Dy³⁺increased to 3%mol,the concentration quenching effect would be induced and the luminescent intensity decrease.The research that the effect of different concentrations of Mg²⁺and Zn²⁺on CaTiO₃:Dy³⁺phosphor was conducted.The samples synthesized by adding Mg²⁺and Zn²⁺with different concentrations（0%mol-10%mol）were studied.The results show that the doping of Mg²⁺and Zn²⁺couold improve the luminescence intensity of CaTiO₃:Dy³⁺phosphors,and the optimum doping ratio is 4%mol.In addition,the CIE coordinates show that Mg²⁺and Zn²⁺could not change the light color significantly.The red light element of CaTiO₃:Dy³⁺phosphors is supplemented by doping Pr³⁺ions（0.1%mol-3%mol）,which could effectively improve the luminescence properties of CaTiO₃:Dy³⁺phosphors.The analysis result indicates that there is no influence on the crystal structure of CaTiO₃:Dy³⁺phosphors by co-doping Pr³⁺ions.And when the concentration of Pr³⁺is 0.1%mol,the luminescence properties of CaTiO₃:Dy³⁺phosphors is the best.The optimized synthesis temperature and holding time is 900°C and 60 min via comparing the influence of different synthesis temperature and holding time on the luminescence properties of CaTiO₃:Dy³⁺phosphors.Based on above researches,M⁺（M⁺=Li⁺,Na⁺,K⁺）with different concentrations（0%mol-7%mol）.is doped in CaTiO₃:Dy³⁺phosphors as charge compensation.The result shows that M⁺（M⁺=Li⁺,Na⁺,K⁺）could effectively improve the crystallinity and luminescence properties of CaTiO₃:Dy³⁺phosphors,the best doping concentration of Li⁺,Na⁺,K⁺all are 1%mol.Among them,Li⁺has the best effect on enhancing the luminescence intensity of CaTiO₃:Dy³⁺,Pr³⁺phosphors.White light emitting phosphors CaTiO₃:Dy³⁺which could be excited effectively by UV light,have excellent luminescence properties.The luminescecnce of CaTiO₃:Dy³⁺could be adjusted to be suitable for different application via doping Mg²⁺,Zn²⁺,Pr³⁺,and alkali metal M⁺（M⁺=Li⁺,Na⁺,K⁺）.It has potential in the white LED.