Mengxin Liu,Jiejun Pan,Xinan Shi,Bingsuo Zou,Daocheng Pan
Rare-earth doped metal oxide nanocrystals with high visible luminescence have been widely used in lighting and display applications owing to their low toxicity, and excellent thermal and chemical stability. However, the room-temperature preparation of near-infrared (NIR) luminescent rare-earth doped metal oxide nanocrystals remains a challenge. Herein, sub-4 nm Yb 3+ /Nd 3+ -doped CaMoO 4 nanoparticles are prepared by a facile room-temperature ligand-assisted coprecipitation method, which can be completed within 1 min under ambient conditions. Short-chain butyric acid and butylamine as binary ligands play a crucial role in the synthesis of NIR luminescent nanoparticles. The as-prepared nanocrystals can be well dispersed in organic solvents such as chloroform since they are capped with butyric acid and butylamine. The energy transfers from MoO 4 2 − ${\rm MoO}^{2-}_{4}$ ions to Yb 3+ and Nd 3+ ions are systematically investigated in CaMoO 4 :Yb 3+ and CaMoO 4 :Nd 3+ nanoparticles, respectively. More importantly, this ultrafast and room-temperature synthesis strategy is particularly suitable for the large-scale preparation of Yb 3+ /Nd 3+ -doped CaMoO 4 nanoparticles (≈23 g) with NIR emission, which provides new ideas and possibilities for the commercial production of extremely small and NIR-emitting nanophosphors.
One-dimensional CaMoO 4 :RE 3+ (RE = Eu, Sm, Dy, Tb) nanofibers were successfully synthesized through a facile supersaturated recrystallization process. These CaMoO 4 :Ln 3+ nanofibers have the length ranging from 40 to 70 nm and the width of nearly 2 nm. Under UV excitation, these single-doped CaMoO 4 nanofibers shown stronger emission, and the photoluminescence quantum efficiency is 25.7% (CaMoO 4 :Eu 3+ ), 22.4% (CaMoO 4 :Sm 3+ ), 23.2% (CaMoO 4 :Dy 3+ ) and 27.7% (CaMoO 4 :Tb 3+ ), respectively. Moreover, our work reveals that various emission colors can be obtained and tuned from pure red to delight green via co-doping Tb 3+ and Eu 3+ in the CaMoO 4 host, and the energy transfer properties from Tb 3+ to Eu 3+ are also demonstrated. Finally, we apply the green CaMoO 4 :Tb 3+ , red CaMoO 4 :Eu 3+ and white CaMoO 4 :0.05Tb 3+ , 0.02Eu 3+ for LED devices, and these nanofiber-based LEDs present high efficiency and stability, which indicates the promising application in future optoelectronic fields.
危险品化学品经营许可证（带存储）