Luminescence properties of CaWO4 and CaWO4:Eu3+ nanostructures prepared at low temperature

The synthesis of luminescence nanostructures is always related with complicated procedures, and it is still challenging to control their luminescence properties by a facile method. In this work, CaWO4:Eu3+ nanostructures with different morphology, structures and sizes were prepared at low temperatures (2 degrees C), and the luminescence properties of the prepared nanostructures were studied. The nanostructure growth can be controlled by pH values of the precursor, reaction temperatures and Eu3+ doping concentrations. Low temperature (2 degrees C) synthesis is believed to control the nanocrystal growth easily due to slow growth process caused by the low temperature. The pH values of the precursor have a significant impact on the structure of CaWO4, leading to the formation of self-assembled microstructures and isolated nanoparticles. CaWO4:Eu3+ nanowires were produced as the Eu3+ doping concentration is 10%. The luminescence properties show that the reaction temperatures and pH values play an important role in the luminescence of CaWO4 host and the energy transfer from the host to Eu3+ leading to the tunable luminescence color from CaWO4:Eu3+. The method developed in this paper is believed to be beneficial for large-scale synthesis of luminescence nanostructures toward white light emitting diode phosphors.