Near-ultraviolet excited Eu3+ doped KSrY(BO3)2 phosphors for solid-state lighting: synthesis, structure and photoluminescent properties

Abstract

A series of KSrY(BO3)2: Eu3+ phosphors have been prepared by the conventional solid-state reaction method for the first time and characterized using X-ray diffraction, UV–Vis absorbance, as well as Photoluminescence techniques. The XRD results indicated that all prepared samples could be attributable to the monoclinic structure in space group P21/m. The combination of first-principles calculations with UV–Vis absorption spectra confirmed the direct band gap characteristic of the phosphors. Upon 394 nm excitation, the 5D0→7F1 transition of the emission spectra dominated when the Eu3+ ions concentration was low, but the 5D0→7F2 transition rapidly increased and dominated with the doping concentration increasing. When the concentration of Eu3+ ions was 40%, the phosphors has the best luminescence and its CIE chromaticity coordinates were located at (0.6399, 0.3584), the color purity was as high as 99.9%. In addition, correlated color temperature, decay properties and Judd–Ofelt (J–O) theory were discussed in detail.