This study presents a numerical investigation of the influence of ZnS particle size on the optical performance and color quality of phosphor-converted white light-emitting diodes (pc-WLEDs) using Mie-scattering theory combined with Monte Carlo optical simulations. The effects of ZnS particle size on light-scattering behavior, luminous flux, color rendering index (CRI), and color quality scale (CQS) have not been systematically evaluated. The simulation results indicate that increasing the ZnS particle size enhances light scattering but simultaneously reduces luminous flux and degrades color uniformity and color-rendering performance. In contrast, smaller ZnS particles exhibit lower scattering coefficients while maintaining higher luminous output, CRI, and CQS values. These findings demonstrate the trade-off between scattering enhancement and optical performance and highlight the importance of optimizing ZnS particle size to achieve an appropriate balance between luminous efficiency and color quality in pc-WLEDs. The results provide useful design guidelines for the development of high-performance phosphor-converted pc-WLEDs. Future work should focus on experimental validation and the investigation of hybrid scattering-particle systems for further performance enhancement.
