Structural and luminescent properties of solid-solution phosphor BaxSr1-xAl2O4: Eu2+

Solid-solution BaxSr1−xAl2O4 doped with Eu2+ phosphors with various x were successfully synthesized via conventional solid-state method. The structural properties were characterized by X-ray diffraction and the luminescent properties were studied via photoluminescence spectra. We observed an obvious phase transition in the solid-solution BaxSr1−xAl2O4 host, and the turning point located at around x = 0.45, which fitted well with our calculated result based on DFT approach. In addition, the photoluminescence emission spectra witnessed a non-monotonous shift of peak's position with various compositions. The non-monotonicity was not due to structural anomaly as all the samples were confirmed to be solid-solutions by XRD measurements. Our analysis suggests that the non-monotonous spectral shift is mainly determined by the site Eu2+ ions opt to occupy in the solid-solution.