Vol. 5 No. 1 (2027): Future Issue: March

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.

Microwave-assisted preparation of bimetal ZnO-SiO2-pillared montmorillonite using Indonesian natural montmorillonite has been performed. The preparation was proceeded by directly dispersion of zinc oxide and tetraethyl ortho silicate as silica precursors into montmorillonite suspension with tetramethyl ammonium hydroxide followed by microwave irradiation. The effect of zinc content in the nanocomposite was studied by investigating the structure, surface textural, and surface acidity by employing x-ray diffraction (XRD), scanning electron microscopy-energy dispersive x-ray (SEM-EDX), gas sorption analysis, and pyridine adsorption-Fourier-transform Infra-Red (FTIR) method. The results of characterization notified the increasing basal spacing d₀₀₁ of montmorillonite from 1.27 nm into 2.72 nm and 2.43 nm for zinc content of 5 mmol/g and 10 mmol/g, respectively. The higher zinc content is attributed to the increasing specific surface area and surface acidity which contributed to the significantly increasing catalytic activity. The conversion of 99.99% and selectivity to produce isopulegol of 66.39% were achieved as optimum activity of the time-efficient prepared pillared montmorillonite.