Kinetic Control over YVO4:Eu3+ Nanoparticles for Tailored Structure and Luminescence Properties

A series of nanocrystals Y1-xEuxVO4 (x = 0-0.1) were prepared by isothermal and isochronal hydrothermal reactions using citric acid as the capping agent. All nanocrystals were controlled to show particle sizes ranging from 7 to 36 run, which gives rise to the grain growth kinetics in terms of an equation, D-5 = 6.71(5) + 2.82 x 10(10)t exp(-51.50/RT) for x = 0.05. Structural refinements of these nanocrystals demonstrate that as particle size reduces, there appeared an abnormal lattice expansion. The expansion rate is strikingly dependent on the substitution content of Eu3+ in Y1-xEuxVO4. Namely, higher Eu3+ content led to a larger lattice expansion. With these structural changes, nanocrystals of Y0.90Eu0.10VO4 were found to show the maximum luminescence performance as represented by a long lifetime of 1.33 ms. The findings reported in this work are fundamentally important, which might be extended to other doped phosphors with controlled grain growth kinetics for advanced properties.