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

Well-dispersed YVO4:Eu3+ nanoparticles (NPs) of about 8 nm were synthesized by a precipitation reaction and they were coated with SiO2 by a reverse microemulsion method. The thickness of SiO2 shells was altered by changing the molar ratio of tetraethoxysilane (TEOS)/YVO4:Eu3+. The influence of SiO2 coating on the photoluminescence properties of the YVO4:Eu3+ NPs was studied in detail. With the increase of the SiO2 shell thickness, the intensity ratio of 5D0-7F2/5D0-7F1 becomes lower. It was interesting to observe that the quantum yield of naked YVO4:Eu3+ is higher than that of YVO4:Eu3+@SiO2 nanocomposites, and the result is opposite to a previous reference.