Facile hydrothermal synthesis for size-controlled YVO₄:Eu³⁺ micro/nanosheets and its luminescence properties

Homogeneous and size-controlled YVO₄:Eu³⁺ micro/nanosheets were successfully synthesized on a large scale by using an ammonium oxalate (AO)-assisted hydrothermal route and post-calcination process. In this study, the shape and size of the as-prepared architectures can be changed effectively by controlling a series of experimental parameters, such as the precursor’s reaction temperature, hydrothermal reaction time and molar ratio of organic additive AO:Y³⁺. YVO₄:Eu³⁺ micro/nanosheets were synthesized with lengths ranging from 2000 to 400 nm and thicknesses ranging from 200 to 50 nm. When changing the precursor’s reaction temperature and reducing the hydrothermal reaction time to 2 h, the phase composition was transformed into Y₂O₃ instead of YVO₄. Functioning as a precipitant and shape modifier, AO exerted a dynamic effect by adjusting the growth rate of different facets under the various experimental conditions, resulting in the formation of different shapes and sizes of the final products. The correlative growth mechanism was analyzed in detail. Photoluminescence and Electroluminescence properties of the products exhibited a strong red emission focused on 618 nm under 275 nm ultraviolet excitation or direct current high-voltage field. Small sample sizes exhibited high EL intensity. The size-controlled products synthesized successfully via the hydrothermal method could provide a great opportunity for systematically evaluating their luminescence properties and accelerating the use of different types of applications in color display devices.