This study proposes a Dispersion-Induced Decarburization (DID) process using polar solvents to address the degradation of luminescence efficiency in SrAl₂O₄:Eu phosphors caused by carbon contamination from carbon crucibles during high-temperature synthesis. Conventional high-temperature oxidation treatments are effective for carbon removal but induce the oxidation of Eu²⁺ ions and structural collapse of the SrAl₂O₄ host, resulting in severe degradation of luminescence properties. The proposed DID process physically removes carbon impurities by dispersing SrAl₂O₄:Eu powders in highly polar solvents such as distilled water (DI), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), and N,N-dimethylformamide (DMF). Among them, DI exhibited the highest purification efficiency, completely eliminating carbon-related diffraction peaks. As a result, the photoluminescence quantum yield (PLQY) of SrAl₂O₄:Eu improved from 32 % to 50 %, and a maximum PLQY of 55.2 % with a luminance of 6,000 cd･m^-2 was achieved for the 20 mol% Eu-doped powder. This work presents a novel and effective purification strategy that overcomes carbon contamination in SrAl₂O₄:Eu phosphors, significantly enhancing their luminescence efficiency without structural damage.