Phosphor-converted white light-emitting diodes (pc-WLEDs) require an appropriate balance between luminous output and color uniformity to achieve high-quality white light performance. Light scattering within the phosphor layer plays an important role in redistributing emitted photons and consequently affects the angular color characteristics and optical output of the device. In this study, Fe₂O₃ particles were numerically investigated as scattering particles in a 4000 K phosphor-converted white LED over a concentration range of 2–16 wt.%. The optical behavior of the particles was evaluated through their scattering coefficient, reduced scattering coefficient, and particle number density, followed by an analysis of the resulting CCT, ΔCCT, lumen output, color quality scale (CQS), color rendering index (CRI), and spectral power distribution. The simulation results show that increasing the Fe₂O₃ concentration enhances the scattering response and substantially modifies the angular distribution of the emitted light. The CCT exhibits concentration-dependent angular variations, while the ΔCCT indicates that an intermediate Fe₂O₃ concentration provides improved color uniformity. In contrast, the lumen output decreases progressively with increasing Fe₂O₃ concentration. The CQS shows a slight improvement, whereas the CRI exhibits a gradual decrease. These results demonstrate that Fe₂O₃ concentration provides an effective means of controlling the scattering characteristics and color performance of pc-WLEDs, although a trade-off exists between color uniformity and luminous efficiency. The numerical results provide useful guidance for optimizing Fe₂O₃ scattering particles in phosphor-converted white LED systems.

Nguyen Thi Phuong Loan,"Numerical Investigation of Fe₂O₃ Scattering Particles for Optical Performance Optimization of 4000 K Phosphor-Converted White LEDs" International Journal of Advanced Multidisciplinary Research and Educational Development, V2(5): Page(270-276) September - October 2026. ISSN: 3107-6513. www.ijamred.com. Published by Scientific and Academic Research Publishing.