Effects of barium on luminescent properties of Sr2−xBaxSiO4:Eu2+ nanoparticles

Sr2−xBaxSiO4:Eu2+ nanopowders were synthesized by a co-precipitation method using alkaline earth metal nitrates, europium nitrate hydrate, and 3-aminopropyltriethoxysilane (APTES) as starting materials. The substitution of Ba2+ ions for Sr2+ ions caused the phase transition from β- to α′-Sr2SiO4. SEM micrographs exhibited uniform anisotropic nanoparticles with high aspect ratios. The photoluminescence (PL) excitation spectra of Sr2−xBaxSiO4:Eu2+ consisted of two bands originated from Eu(I) and (II) sites, respectively, resulting in two corresponding emission bands at around 473 and 543 nm. The PL spectra exhibited the red- or blue-shift of dominant emission wavelengths, depending on the Ba2+ content.