CdWO₄:Eu³⁺ Nanostructures for Luminescent Applications

CdWO4 as one typical metal tungstate has been extensively studied since it shows great potential to be applied in various luminescent applications (e.g., optical sources, optoelectronics, catalysis, and sensors). However, their luminescence properties are significantly dependent on their structure, shape, and size. Also, the complicated synthesis procedures have limited their practical applications. In our study, different reaction conditions enable CdWO4:Eu3+ nanocrystals to possess different morphologies and sizes. The CdWO4:Eu3+ nanoparticles and nanorods can be formed by tuning the precursor pH values. Furthermore, under different reaction temperatures, the as-synthesized CdWO4:Eu3+ nanostructures show different sizes. The large-sized CdWO4:Eu3+ nanorods were produced as the pH value is 4 and the temperature is 150 °C. The luminescence properties of the obtained nanocrystals were also systematically studied. Under a single wavelength excitation, the CdWO4:Eu3+ nanocrystals show the multicolor luminescence performance. This is because the energy transition between the tungstate group and Eu3+ ion was controlled by tuning reaction conditions. The facile method developed in this work provides important insights into designing doped nanocrystals toward luminescent applications in light sources, phosphors, and optical devices.