Effect of PO43−/VO43− proportion on structure and photoluminescence properties of Gd(PyV1−y)O4: X at.% Tm3+ phosphors

A series of Gd(PyV1−y)O4: x at.% Tm3+ (x = 1, 2, 3, 4 and 5; y = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1) phosphors were prepared by chemical co-precipitation method. The phosphors were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, photoluminescence excitation and emission spectroscopy. XRPD result suggests that when the concentration ratio of VO43− to PO43− exceeds 3∕7, the crystal structure of phosphors changes from monoclinic structure to tetragonal structure. Tm3+ ion has a typical blue emission peak around 477 nm, which is caused by the transition of 1D4→3H6 energy level. By mixing PO43− and VO43− groups, the photoluminescence intensity and color purity of the phosphors are improved, and the optimal PO43− to VO43− concentration ratio is identified to be 1∕9. Different concentrations of Tm3+ were then used as activating ions of Gd(P0.1V0.9)O4 matrix, and the quenching concentration is found to be 2 at.%, with the quenching mechanism being revealed to be dipole-dipole interaction. •Tm3+ doped Gd(P,V)O4 blue phosphors with higher purity were prepared.•Photoluminescence intensity and color purity of the phosphors are improved.•Optimal composition of the matrix was determined.•The concentration quenching mechanism of Tm3+ was confirmed.