<p>Highly intense red-emitting TiO₂:Eu³⁺ nanophosphors were synthesized via a facile co-precipitation method by varying the Eu³⁺&#xa0; concentration from 1 to 5&#xa0;at.%. X-ray diffraction and micro-Raman analyses confirmed the formation of phase-pure anatase TiO₂ with tetragonal structure for all compositions. Eu³⁺ incorporation suppressed grain growth and induced a morphology transition from nearly spherical nanoparticles to platelet-like structures, reflecting dopant-modified growth kinetics. Optical investigations revealed a concentration-dependent widening of the band gap, governed by the combined effects of carrier-induced Burstein–Moss shift and defect-related electronic structure modification. Photoluminescence studies exhibited intense red emission dominated by the hypersensitive ⁵D₀ → ⁷F₂ transition, confirming that Eu³⁺ ions occupy low-symmetry, non-centrosymmetric environments within the TiO₂ lattice. A pronounced enhancement in emission intensity and quantum efficiency was achieved at an optimal Eu³⁺ concentration of 4&#xa0;at.%, where the luminescence intensity was approximately four times higher than that of the 1&#xa0;at.% doped sample. Judd–Ofelt analysis yielded Ω₂ &gt; Ω₄ for all compositions, consistent with the enhanced hypersensitive ⁵D₀ → ⁷F₂ emission. Radiative parameter evaluation revealed a maximum quantum efficiency of 86.8%, prolonged lifetime, and suppressed non-radiative losses at the optimal composition. The optimized phosphor exhibits CIE chromaticity coordinates of (0.663, 0.336), a correlated color temperature of 2787&#xa0;K, and high color purity (96.4%), demonstrating its potential as an efficient red-emitting material for solid-state lighting and optoelectronic applications.</p> Graphical abstract <p></p>