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

Abstract

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 °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 °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.