Different alkali carbonates on the microstructure and photoluminescence properties of BaY₂ZnO₅:Tb³⁺ phosphors prepared using the solid-state method

For this study, different alkali carbonates (Li₂CO₃, Na₂CO₃, and K₂CO₃) were added to a Tb³⁺ activated BaY₂ZnO₅ phosphor synthesized using the solid-state reaction, and the morphology and photoluminescence properties of BaY₂ZnO₅:Tb³⁺ phosphors are investigated and discussed. When BaY₂ZnO₅:Tb³⁺ phosphors to which alkali carbonates were added were sintered at 1250 °C for 12 h, X-ray powder diffraction analysis showed that the unreacted Y ₂O₃ raw material decreased, and scanning electron microscopy (SEM) showed that large particle sizes and necking shapes were obtained. Emission intensities decreased, and the wavelengths of the excitation peaks changed when alkali carbonates were added to BaY₂ZnO ₅:Tb³⁺ phosphors. The excitation peaks of phosphors prepared with alkali carbonates were shifted to a short wavelength because the addition of alkali ions may increase the oxygen vacancy in BaY ₂ZnO₅:Tb³⁺ phosphors and change the photoluminescence properties. The CIE chromaticity (x,y) is (0.35,0.55), and does not change with the addition of alkali carbonates.