Eu3+, Li+ doped CaWO4 nanorods: Synthesis, emission-decay curves and effective-refractive index

• CaWO4 nanorods were synthesized via a oleic acid-assisted solvethermal route.
• The excitation spectra of nanorods and bulk phosphors have been analyzed carefully.
• The 5D0 decay time of Eu3+ was detected under different compactness conditions.
• According to the virtual-cavity model, effective-refractive index was estimated.

In the present paper, CaWO4: Eu3+, Li+ nanorods have been successfully synthesized via an oleic acid (OA)-assisted solvethermal route. The transmission electron microscope (TEM) photograph shows that the CaWO4: Eu3+, Li+ nanorods are monodisperse and uniform nanorods with average diameter of 26 nm. The optical properties of Eu3+ in CaWO4 samples, including photoluminescence (PL) excitation spectra and luminescent decay curves, are investigated in detail. Due to the form of the nanorods, the relative contribution of CTB to the nanorods sample is greater than that to the bulk counterparts. The decay time of the 5D0 level (ranging from 0.94 to 0.65 ms, depending on the filling factor of the nanorods) of the nanorods is longer than that of the bulk counterpart mainly due to the reduction in the size of the nanorods, which introduces an effective-refractive index smaller than the refractive index of CaWO4.