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 degrees C for 12 h, X-ray powder diffraction analysis showed that the unreacted Y2O3 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 BaY2ZnO5: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 BaY2ZnO5:Tb3+ phosphors and change the photoluminescence properties. The CIE chromaticity (xy) is (0.35,0.55), and does not change with the addition of alkali carbonates. (C) 2012 Elsevier Ltd. All rights reserved.