Rapid, morphologically controllable, large-scale synthesis of uniform Y(OH)3 and tunable luminescent properties of Y2O3:Yb3+/Ln3+ (Ln = Er, Tm and Ho)

Abstract

In the present paper, we first demonstrate a facile and rapid precipitation process to fabricate Y(OH)₃ with tailored well-defined shapes and excellent uniformity in the presence of sodium citrate. The morphologies and sizes of the products can be controlled by simply tuning the sodium citrate amounts, the reaction temperature, and the amount of NaOH. After calcination, the Y(OH)₃ precursors were easily converted to pure Y₂O₃ with no obvious change in morphology. The phases, morphologies, sizes as well as up-conversion (UC) photoluminescence of as-prepared products were well characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectra, respectively. The UC emission properties of the prepared Y₂O₃:Yb³⁺/Ln³⁺(Ln = Er, Tm and Ho) were investigated in detail. Under 980 nm NIR excitation, the emission intensity and the corresponding luminescent colors of Y₂O₃:Yb³⁺/Ln³⁺ (Ln = Er, Tm and Ho) could be precisely modulated by changing the doping concentration of Yb³⁺ ions. Furthermore, the experimental results also reveal that the optical properties of the Y₂O₃:1%Yb³⁺/1%Ho³⁺ phosphors with different morphologies are strongly dependent on their morphologies and sizes.