The influence of additives on the morphology and luminescence of phosphors synthesized via microdroplet spray pyrolysis

A ternary CA/Ur/DMF additive system enables effective particle engineering of Y 2 O 3 :Eu 3+ phosphors via spray pyrolysis. • Synergistic additive decomposition promotes particle densification and controlled crystallization behavior. • Uniform, dense spherical particles with reduced internal defects are achieved using the ternary additive strategy. • An additive-assisted strategy is proposed for microstructural optimization of functional oxide powders. This study examines the role of organic additives in regulating particle formation, microstructure, and photoluminescence (PL) performance of Y 2 O 3 :Eu 3+ phosphors prepared by microdroplet spray pyrolysis. Citric acid (CA), urea (Ur), and DMF were introduced as single and ternary additives. Thermal behavior, phase composition, and particle characteristics were systematically analyzed using TG, XRD, SEM, TEM, and particle size analysis. The CA\Ur\DMF ternary system yields the highest PL intensity and the smallest crystallite size (~24 nm), outperforming single-additive systems. TG results indicate synergistic decomposition behavior that promotes particle densification and suggests a reduction in structural defects. Morphological observations reveal uniform, dense spherical particles with homogeneous elemental distribution. These results demonstrate an effective additive-assisted strategy for microstructural control and performance optimization of phosphor powders.