Strong luminescence enhancement of Li2CaSiO4:Eu2+ phosphors by codoping with La3+

La³⁺ ions codoped Li₂CaSiO₄:Eu²⁺ phosphors were synthesized through the solid state reaction method. Large increases in the emission could be achieved by adding La³⁺ in the host. The optimum doping concentration expressed by the x value in Li₂Ca_0.99?xSiO₄:0.01Eu²⁺, xLa³⁺ was determined to be of 0.01. X-ray diffraction patterns revealed that the samples maintained Li₂CaSiO₄ single phase after codoping Eu²⁺ and La³⁺. The excitation spectra of samples showed a broad absorption band ranging from 220 to 450 nm and the emission spectra excited at 375 nm showed the typical broad band of Eu²⁺ peaks at about 478 nm (4f⁶5d¹–4f⁷). The broad absorption band wavelength was found to be matched appropriately with the emission wavelength of commercially available blue LEDs. Fluorescent lifetime test results showed that the La³⁺ codoped could increase the excited state energy and prolong the lifetime of Eu²⁺. The optimization mechanism was studied in detail by the case of La³⁺ codoping. The temperature dependent luminescence measurements show that the thermal quenching remains small in the case of La³⁺ doping, in other word, La³⁺ codoped Li₂CaSiO₄:Eu²⁺ phosphor has a good thermal stability. These results provided a useful basis for further improving the luminescence performance of Li₂CaSiO₄:Eu²⁺ phosphors.