Synthesis and Optical Properties of a Solid Solution between Boron and Aluminum in NaBa(B9-xAl1-x)O15: Eu2+



Journal Title

Journal ISSN

Volume Title



Solid state white lighting replaces traditional fluorescent and incandescent lighting due to its higher efficiency and longer lifetimes. One method used to produce solid state white light is combining a near-UV LED with three inorganic phosphors emitting blue, green, and red. The three phosphors incorporated into this device must be efficient with a high photoluminescent quantum yield. NaBaB9O15 was synthesised doped with 3% Eu2+ and determined to have a 95% quantum yield, excellent thermal stability, but emitted a violet-color. NaBaB9O15 has [B3O7]5- units with two triangular structures with one tetrahedral. Aluminum was incorporated into NaBaB9O15 to fill in the tetrahedral units forming a solid solution between boron and aluminum and to shift the emission towards red. 5% and 10% aluminum concentrations were added to NaBa(B1-xAlx)9O15. These were obtained through traditional high temperature solid state synthesis and confirmed as pure by powder x-ray diffraction and subsequent Le’Bail refinement. The volumes of each cell was determined to increase as aluminum increased. Photoluminescent measurements reveal that, when excited with 315 nm NaBaB9O15:Eu2+ is a violet color, NaBa(B0.95Al0.05)9O15:Eu2+ is blue-violet, and NaBa(B0.9Al0.1)9O15:Eu2+ is blue. This indicates that the higher the aluminum concentration, the more red shifted the compound is.