Synthesis and photoluminescence properties of core–shell structured YVO4:Eu3+@SiO2 nanocomposites

Well-dispersed YVO 4 :Eu 3+ nanoparticles (NPs) of about 8   nm were synthesized by a precipitation reaction and they were coated with SiO 2 by a reverse microemulsion method. The thickness of SiO 2 shells was altered by changing the molar ratio of tetraethoxysilane (TEOS)/YVO 4 :Eu 3+ . The influence of SiO 2 coating on the photoluminescence properties of the YVO 4 :Eu 3+ NPs was studied in detail. With the increase of the SiO 2 shell thickness, the intensity ratio of 5 D 0 - 7 F 2 / 5 D 0 - 7 F 1 becomes lower. It was interesting to observe that the quantum yield of naked YVO 4 :Eu 3+ is higher than that of YVO 4 :Eu 3+ @SiO 2 nanocomposites, and the result is opposite to a previous reference.