Enhancement of photoluminescence of Ba2SiO4:Eu2+ by co-doping of La3+ or Y3+

Green light-emitting Ba2SiO4:Eu2+ phosphors co-doped with La or Y were synthesized by conventional solid-state reaction technique in reductive atmosphere (a mixture of 5% H2 and 95% N2). The results showed that the co-doping of La and Y could greatly enhance the fluorescence intensity of Ba2SiO4:Eu2+ phosphors. The optimum doping concentration expressed by the x value in (Ba0.985–1.5xREx)2SiO4: 0.03Eu2+ (RE=La or Y) was determined to be of 0.05. The excitation and emission peaks of all as-synthesized phosphors were wide bands. The excitation bands ranged from 250 to 400 nm, which matched well with the wavelength of near ultraviolet white light-emitting diodes (LED) chip and could be used as a potential candidate for the fabrication of white LED. The emission bands from 450 to 550 nm were typical 5d–4f transition emission of Eu2+ and displayed un-symmetry profiles because of the two substitution sites of Ba2+ with Eu2+.