Possibility of adjusting photoluminescence spectra of Ca scheelites (CaMoO4: Eu3+ and CaWO4: Eu3+) to the emission spectrum of incandescent lamps

Abstract

The peculiarities of the photoluminescence of compounds CaMoO4: Eu3+ and CaWO4: Eu3+ with the scheelite structure associated with a change in the short- and long-range orders of the crystal lattice upon a change in the activator (Eu3+) of the photoluminescence range in the interval 1–4 mol %, in which the photoluminescence of the matrix is preserved in the range 484–557 nm, are investigated using X-ray phase analysis as well as photoluminescence, Raman, and diffuse reflection spectroscopies. The introduction of Eu3+ ions leads to the reconstruction of the lattice so that up to 10% of these ions stimulate the formation of centrosymmetric localization upon the substitution of Ca2+ ions in the noncentrosymmetric positions. It is found that the spectral radiant emittance of the more effective luminophore CaMoO4: Eu3+ can be adjusted to this parameter for an incandescent lamp for the Eu3+ concentration of 1–2 mol %.