Study On Structure,spectral Characteristics And Energy Transfer Mechanism Of SrLa₄Si₃O₁₃:Eu³⁺,Tb³⁺

White light-emitting diode（LED）has the advantages of high efficiency,low energy consumption,no pollution and long life,make it become the global semiconductor lighting field and the fourth generation of solid light source.At present,the commercial white LED is made up of blue light LED chip and yellow phosphor YAG:Ce³⁺.Phosphor is an important part of LED,and its performance has great influence on LED emission.Due to the lack of red light in the YAG phosphor luminescence spectrum,it is not conducive to the health of the human eye because of the cold white light.The commercial LED has low color rendering index and higher color temperature and other shortcomings,in order to solve these problems,researchers are committed to the development of new system and excellent performance of fluorescent powder.White LED chip works at 150 C temperature,so its physical,chemical stability is extremely important.However,Silicate has the advantages of physical and chemical stability,and the cost is low.So,in this paper,the luminescent properties and energy transfer mechanism of red,green and yellow phosphors were studied by selecting SrLa4Si3O13 as host,and adding the single doped with Eu³⁺,Tb³⁺ ions and two ions co-doped,respectively.Specific content as follows:（1）SrLa_4-xSi₃O₁₃:xEu³⁺ red phosphor was prepared by high temperature solid state method in air atmosphere.Using X ray diffraction,fluorescence spectrum and excitation spectra and thermal quenching system to determine the crystal structure,excitation and emission spectra and lifetime and thermal stability was studied and tested.The results of XRD showed that the sample was the fluorescent powder structure what we need.The excitation spectra of the samples indicate that the phosphor can be excited by UV（393nm）and blue light（462nm）respectively.And the strongest emission peak is located at about 615 nm.The energy transfer type can be calculated by spectral analysis of phosphor.The samples have good thermal stability.So the phosphor can increase the red component of the three primary colors in white LED,can also be added to the YAG,increase the red component of the emission spectrum of,and improve the color rendering index LED.（2）Preparation of SrLa_4-xSi₃O₁₃:xTb³⁺ phosphor by high temperature solid state method in air atmosphere.XRD,fluorescence spectra,lifetime decay and thermal stability of the samples were tested.The results of XRD showed that the sample was the fluorescent powder structure what we need.The results of fluorescence spectra show that the phosphor can be excited by UV.The strongest emission peak is located at 544 nm..The life time of the samples is 6.5μs.Through the Arrhennius model fitting,the samples activation energy ΔE is about 0.74 eV,so that the sample has well thermal stability.So Sr La4-xSi3O13:xTb³⁺ can be used as green phosphor assembly UV excitation three color white LED.（3）Phosphor SrLa_3.6-xSi₃O₁₃:0.4Tb³⁺,xEu³⁺ was prepared by high temperature solid-state method based.The energy transfer mechanism and spectral regulation between Tb³⁺ and Eu³⁺ were studied.The samples were analyzed by XRD and Rietveld,and the results showed that the sample was the phosphor structure what we need.The fluorescence spectrum test results show that with the increase of the concentration of Eu³⁺,the luminescence intensity is enhanced.The results of fluorescence spectra show that with the increase of Eu³⁺ concentration,the emission peak intensity of Eu³⁺ ion increases and the intensity of Tb³⁺ emission peak decreases,which indicates that the energy transfer direction is Eu³⁺ to Tb³⁺.Calculate and observe the energy transfer efficiency of different Eu³⁺ ion concentration,also can be explained by a direction of energy transfer Eu³⁺ to Tb³⁺.The energy transfer mode of Eu³⁺ to Tb³⁺ is electric dipole electric dipole interaction,the sample life is 40.09μs.When the Eu³⁺ ion concentration is 0.02,the emission spectrum CIE coordinate of the sample is（0.39,0.45）,emitting yellow light.Therefore SrLa_4-xSi₃O₁₃:xTb³⁺ can be used as yellow phosphor assembly UV excitation three color white LED.