Synthesis And Properties Of CaLa₄Si₃O₁₃:Eu Red Phosphors For White LEDs

White light emitting diode (WLED) is considered as the next-generation of lighting source due to the characteristics of small volume, long service lifetime, energy conservation and pro-environment etc. Phosphor-conversed light emitting diode (pc-LED) has been practically used for the main method to realize white light emitting. Considering the process, cost, technology status etc, pc-LED is the focus of the research at the moment. At the present stage WLED development tendency is the pursuit of high color rendering index (CRI), low color temperature (CT) and high power, and the characteristics of red emitting phosphor are the most significant influence for CRI and CT. Consequently, searching for the red emitting phosphor, which can be effectively excited by blue LED and UV-LED, is a critical research topic for WLED lighting.Phosphor CaLa4Si3O13:Eu3+was prepared via solid-state reaction in this thesis. The effects of the total of double flux, molar ratio of Li and B in the flux, and sintering temperature on the luminescent properties were investigated. The appropriate synthesis conditions are confirmed as that the ratio of Li and Bis1:1in mole and the amount of double flux is0.4mol·mol-1and pre-sintered at950℃for150min and then sintered at1150℃for240min. And Eu3+optimal concentration is0.5(CaLa3.5Si3O13:Eu0.53+). The influence of some aspects on the crystal constitution and luminescence performance has been investigated, such as the substitution of part of apatite cation for Sr2+, Ba2+ions. The analysis of crystal structure and luminescence performance shows that Sr2+, Ba2+ions can completely replace Ca2+ions. The lattice parameter of samples have a linear relationship with the concentration of Sr2+, Ba2+ions substitution, however, the intensity of emission spectra increased first and then decreased with the concentration of Sr2+ions substitution, and increased with the concentration of Ba2+ions substitution all the while.Ca-(RE, Eu)-apatites(RE=La, Y,Gd) as part of the reduction of Eu3+study on luminescence properties with matrix of Eu2+, Eu3+ions, and find that exciting Eu2+in addition to get common5Do emission from Eu3+, also got novel5D1strong emission of Eu3+sensitized by Eu2+.