<p>In this study, Sm³⁺-doped magnesium germanate (Mg₂GeO₄) nanophosphors were synthesized using a rapid solution combustion method. Rietveld refinement of the doped-Mg₂GeO₄ sample revealed an orthorhombic crystal structure. Scanning electron microscopy (SEM) images of the nanophosphors revealed predominant spherical morphology with uniform size distribution. High-resolution transmission electron microscopy (HRTEM) analysis showed well-resolved lattice fringes with an interplanar spacing of ~ 0.24&#xa0;nm, indexed to the (121) plane. The slight variation in the energy band gap (E_g) from 4.21 to 4.12&#xa0;eV with increasing dopant concentration was clearly witnessed. Photoluminescence (PL) emission studies under 409&#xa0;nm excitation wavelength exhibited strong red emission centered around 665&#xa0;nm, corresponding to the ⁴G_5/2→⁶H_9/2 transition of Sm³⁺ ions in the host lattice. The optimal luminescence intensity was observed in the sample doped with 3&#xa0;mol % of Sm³⁺ ions. The higher doping concentrations beyond 3 mol % led to concentration quenching, which decreased the luminescence intensity. The type of interaction responsible for quenching was identified as electric dipole-dipole based on Dexter’s theory. Time-resolved PL measurements revealed a tri-exponential decay behavior, with an average lifetime (τ_avg) of ~ 0.72 ms. Furthermore, the quantum efficiency (QE) of the optimized phosphor was found to be ~ 59.27%. The Commission Internationale de l’Eclairage (CIE) diagrams confirmed emission in the orange-red region, suitable for white light-emitting diodes applications. The obtained results of the prepared phosphors validated their applicability as red-emitting components in solid-state lighting.</p>