Photoluminescence properties of Y0.5−xGd0.35Eu0.15BixNbO4 (0 ≤ x ≤ 0.30) and Y0.35Gd0.35Eu0.15Bi0.15Nb1−yPyO4 (0 ≤ y ≤ 0.20) phosphors

• The phosphors for red light emitting diode.
• The emission intensity for Y0.5−xGd0.35Eu0.15BixNbO4 (0 ≤ x ≤ 0.30) samples is tuned by doping Bi.
• Doping P at Nb site for Y0.35Gd0.35Eu0.15Bi0.15NbO4, the emission intensity is enhanced.

The Y0.5−xGd0.35Eu0.15BixNbO4 (0 ≤ x ≤ 0.30) and Y0.35Gd0.35Eu0.15Bi0.15Nb1−yPyO4 (0 ≤ y ≤ 0.20) phosphors have been synthesized by the conventional solid-state reaction. For these Y0.5−xGd0.35Eu0.15BixNbO4 (0 ≤ x ≤ 0.30) samples, the emission increases and then decreases with increasing Bi content, and the maximum emission is achieved when x is 0.18. As for the Y0.35Gd0.35Eu0.15Bi0.15Nb1−yPyO4 (0 ≤ y ≤ 0.20) samples, the emission and excitation intensities are both varied with the P doping content. The strongest intensity is obtained in the case of y = 0.15. These results indicate that the Bi dopant acts as one sensitizer and enhances the photoluminescence intensity. The introduction of PO43− also plays an important role in the photoluminescence properties of the investigated samples. The relevant mechanism has been also presented.

The emission intensity at 614 nm enhances with the increasing Bi3+ doped content and reaches the highest at x = 0.18, and then gradually decreases with further increases of Bi concentration. That is to say, the optimal Bi3+ doped content in Y0.5−xGd0.35Eu0.15BixNbO4 phosphor in our work is 0.18. The optimal concentration of Bi such as 0.18 can improve the emission intensity 100% higher than the Y0.5Gd0.35Eu0.15NbO4.Both the maximum emission and excitation intensity increase with x and reach a maximum at y = 0.15, and then, it decreases till to y = 0.20. The manner indicates that the absorbed energy by the host material mainly uses for the NbO43− emission, and the introduction of PO4 group affect largely luminescent properties for the Y0.5Gd0.35Eu0.15Nb1−yPyO4 samples.Figure optionsDownload as PowerPoint slide