Applying calcium fluoride and silica particles: A solution to improve color homogeneity of pc-WLEDS

Abstract

This article focuses on enhancing the lighting efficiency of pc-WLEDs, a new and advanced lighting solution that has received lots of attention. To adapt to the demand of modern lighting, the lighting performance of pc-WLEDs must be improved, especially the color homogeneity and luminous flux, two of the most important quality indicators of pc-WLEDs. Through experiments, this article proposes using the scattering enhancement particles (SEPs) such as CaF₂ and SiO₂ with yellow phosphor Y₃Al₅O₁₂:Ce³⁺ in pc-WLEDs configuration. The pc-WLEDs model is created by using the LightTools program and set at 8500 K correlated color temperature, while the experimental results yielded from this simulation will be verified by Mie-scattering theory. The information from this article reveals the scattering coefficients of SEPs at 455 nm and 595 nm wavelengths. Moreover, it is confirmed that the employment of CaF₂ is effective in promoting the color but may damage the luminous efficiency if the concentration is too high while the SEP material, SiO₂, exhibits high luminous efficiency at all concentration.