In this work, a spray-drying method was used to prepare densely structured Zn₂SiO₄:Mn phosphor particles. Several organic materials such as citric acid, sucrose, and dextrin were examined as additives to control the particle morphology. Consequently, dextrin was found to be the most effective organic additive for obtaining dense precursor powders after the drying process. After the heat-treatment process, the dextrin-assisted precursor particles were turned into dense spherically shaped particles with a mean particle size of 1.3 μm and the high crystallinity of a pure Zn₂SiO₄ phase. The luminescence properties were changed by changing the types of organic additives. The phosphor particles with the smallest surface area and the powder with the largest crystallite size showed the highest luminescence intensity. Finally, the dense spherical particles obtained from the spray solution containing dextrin had an emission intensity corresponding to 176% that of the phosphor powders prepared from the solution without the organic additive.