Tb3+ and Sm3+ co-doped CaWO4 white light phosphors for plant lamp synthesized via solid state method: phase, photoluminescence and electronic structure

Abstract A series of CaWO4: Tb3+, Sm3+ phosphors was successfully synthesized via the facile high temperature solid state reaction method. The phase purity and effect of different valence doping on cell parameters were evaluated by XRD analysis. When the trivalent RE3+ replaces the divalent Ca2+, the local electric field is generated, which has obvious influence on the lattice. The excitation spectra show that Tb3+ and Sm3+ can be excited simultaneously in the co-doped phosphors. The emission spectra of phosphors show that white phosphors can be obtained by adjusting the doping ratio and there is an energy transfer from Tb3+ to Sm3+ in the co-doped phosphors. The electronic structures of phosphors were studied by the first principle calculations. The quantum efficiency, thermal dependence and comparison with the absorption spectra of the pigments show that CaWO4: 0.01Tb3+, 0.01Sm3+ phosphor has potential applications in the fields of white LEDs and plant lamps.