Self-assembled growth of LuVO4 nanoleaves: hydrothermal synthesis, morphology evolution, and luminescence properties

Abstract

In the present paper, LuVO₄ nanoleaves have been synthesized via a facile and low-cost complexant-assisted hydrothermal approach. The phases, morphologies, sizes, and luminescence properties of the as-prepared products were well characterized by means of XRD, FT-IR, SEM, TEM, SAED, EDX, HRTEM, PL, and CL. The results indicate that the phase, morphology, and size of the LuVO₄ samples can be tuned in a controlled manner by altering the amount of Na₂tar, the pH value of the initial solution, and the reaction time. The crystal growth was thoroughly investigated, and a possible formation mechanism was proposed. Upon UV and low-voltage electron beam excitation, the LuVO₄:Ln³⁺ (Ln³⁺ = Eu³⁺, Dy³⁺, Sm³⁺, Er³⁺) samples exhibit bright red (Eu³⁺, ⁵D₀ → ⁷F₂), green-yellow (Dy³⁺, ⁴F_9/2 → ⁶H_13/2), orange-red (Sm³⁺, ⁴G_5/2 → ⁶H_7/2) and green (Er³⁺, ⁴S_3/2 → ⁴I_15/2) luminescence. Furthermore, the UC luminescence properties, as well as the emission mechanisms of LuVO₄:Yb³⁺/Ln³⁺ (Ln³⁺ = Er³⁺, Tm³⁺, Ho³⁺) samples, were systematically investigated, which show respective green (Er³⁺, ⁴S_3/2, ²H_11/2 → ⁴I_15/2), blue (Tm³⁺, ¹G₄ → ³H₆) and red (Ho³⁺, ⁵F₅ → ⁵I₈) luminescence under 980 nm NIR excitation. These merits of multicolor emissions in the visible region endow this kind of material with potential applications in the field of light display systems, lasers, and optoelectronic devices.