Monophasic zircon-type tetragonal Eu_1−xBi_xVO₄ solid-solution: synthesis, characterization, and optical properties

Highlights: • Complete Eu_1−xBi_xVO₄ with zircon-type structure was successfully synthesized. • The band gap of the samples could be adjusted and controlled by bismuth content. • Eu_1−xBi_xVO₄ show strong red emission under both near UV and visible-light excitation. - Abstract: By combining the methods of co-precipitation and hydrothermal synthesis methods, the complete solid-solution of Eu_1−xBi_xVO₄ with monophasic zircon-type structure was successfully synthesized. The zircon-type structure was determined by X-ray diffractometer and Raman scattering, and the optical properties were characterized by ultraviolet-visible diffuse reflectance and photoluminescence spectrophotometer. The results indicate that the band gap of Eu_1−xBi_xVO₄ could be adjusted and controlled by bismuth content in the range of x = 0–0.9. Meanwhile, the Eu_1−xBi_xVO₄ solid-solution phosphors show strong red light emission was shown in 619 nm under both near UV-light and visible-light excitation. Notably, the emission intensity of Eu_1−xBi_xVO₄ (x = 0.4) is the strongest in all samples