Brightly luminescent and color-tunable CaMoO₄:RE³⁺ (RE = Eu, Sm, Dy, Tb) nanofibers synthesized through a facile route for efficient light-emitting diodes

One-dimensional CaMoO₄:RE³⁺ (RE = Eu, Sm, Dy, Tb) nanofibers were successfully synthesized through a facile supersaturated recrystallization process. These CaMoO₄:Ln³⁺ nanofibers have the length ranging from 40 to 70 nm and the width of nearly 2 nm. Under UV excitation, these single-doped CaMoO₄ nanofibers shown stronger emission, and the photoluminescence quantum efficiency is 25.7% (CaMoO₄:Eu³⁺), 22.4% (CaMoO₄:Sm³⁺), 23.2% (CaMoO₄:Dy³⁺) and 27.7% (CaMoO₄:Tb³⁺), respectively. Moreover, our work reveals that various emission colors can be obtained and tuned from pure red to delight green via co-doping Tb³⁺ and Eu³⁺ in the CaMoO₄ host, and the energy transfer properties from Tb³⁺ to Eu³⁺ are also demonstrated. Finally, we apply the green CaMoO₄:Tb³⁺, red CaMoO₄:Eu³⁺ and white CaMoO₄:0.05Tb³⁺, 0.02Eu³⁺ for LED devices, and these nanofiber-based LEDs present high efficiency and stability, which indicates the promising application in future optoelectronic fields.