Two new rare-earth oxyborates BaBiTbO(BO) and BaSrBiTbO(BO) and luminescence properties of the BaBiTbEuO(BO) phosphors.

Single crystals of two new terbium oxyborates BaBiTbO(BO) and BaSrBiTbO(BO) were obtained by the high-temperature solution method. They crystallize in the hexagonal 6/ group ( = 2) with lattice parameters of = 5.41865(9) Å, = 26.3535(5) Å, = 670.12(3) Å and = 5.36534(19) Å, = 26.0661(10) Å, = 649.83(5) Å, respectively. Their crystal structures feature two kinds of layers: [Tb(BO)] formed by corner-sharing TbO octahedra and BO triangles, as well as [Bi(BO)O] consisting of BiO dimers and BO groups, with alkali-earth cations sitting inside and between the layers. In addition, solid solutions of BaBiTbEuO(BO) (0 ≤ ≤ 0.2) were prepared the solid-state reaction method. The obtained products were characterized by powder XRD, SEM, IR/Raman, XPS, DRS, and luminescence spectroscopy. It was found that as the Eu doped content varies from = 0 to 0.2, the emission color of the BaBiTbEuO(BO) phosphors can be adjusted from cyan to near-white and then to orange-red or from green to orange and then to red under the excitation of 349 and 377 nm, respectively. Furthermore, the emission intensities and chromaticity coordinates were found to be sensitive to the temperature for the phosphor BaBiTbEuO(BO) upon 377 nm excitation. The above results demonstrate that BaBiTbEuO(BO) phosphors have potential as multifunctional materials for solid-state lighting and temperature sensing applications.