This paper reports the comparative investigations of the structural and spectral properties of Y₃Al₅O₁₂:Eu³⁺ (YAG:Eu) and Y₃Al₅O₁₂:Eu³⁺,Si⁴⁺ (YAG:Eu,Si) phosphors synthesized by combustion method at low temperature. A pure phase was identified for the YAG:Eu phosphor with a suitable amount of SiO₂. Rietveld refinement and analytical calculation of different structural parameters were performed to get the idea about the SiO₂ substitution in YAG:Eu. The characteristic red luminescence corresponding to Eu³⁺ transitions was observed after irradiation with ultra violet (UV) light and enhanced with SiO₂ addition. Jorgensen formula and nephelauxetic ratio were used to understand the ligand behavior of Eu–O bond in YAG doped phosphor. The Judd–Ofelt intensity parameters and color properties of the phosphors were determined in detail. An efficient synthesis method for YAG:Eu phosphor, compatible for industrial applications, was proposed.