Monoclinic Gd_1−xEu_xBO₃ nanopowders were successfully synthesized using a modified Pechini method. The crystal structure of the prepared materials was revised and confirmed using several techniques such as: IR, XRD, TEM, Raman spectroscopy and EDX analysis. The obtained material was comprised of particles, consisting of parts with the average size 350 nm. The luminescence properties of the prepared phosphors with different concentrations of Eu³⁺ ions were characterized by excitation and emission spectra and its kinetic decay. The Judd–Ofelt parameters (Ω₂, Ω₄), quantum efficiency, η, and chromaticity coordinates were also calculated.