[TuP3D] D. Photonic devices and related technologies

[TuP3D-14] Excitation Efficiency Enhancement Enabled by Photonic-Crystal Slab Resonances in Color Conversion Films

Taehun Kim¹, Minhyuk Park¹, 〇Kyungtaek Min¹ (1. Tech Univ. of Korea (Korea))

Improving excitation efficiency in color conversion films is critical for high-brightness micro-LED displays and solid-state lighting. Conventional phosphor layers often exhibit limited excitation-light absorption, restricting overall color conversion performance. In this work, we propose an optical design approach that enhances excitation absorption by exploiting resonant modes supported by a photonic-crystal slab integrated with a color conversion film. A periodic dielectric slab on the phosphor layer forms a leaky slab-waveguide structure that supports band-edge resonances near the excitation wavelength, and finite-difference time-domain simulations are used to optimize the structural parameters so that the slab resonance overlaps with typical blue excitation sources. Near the photonic band edge, reduced group velocity and strong electromagnetic field localization within the phosphor region lead to enhanced interaction between excitation light and the active material. Compared with a flat reference film, the proposed structure exhibits significantly enhanced excitation absorption under both monochromatic and broadband illumination, while remaining effective over realistic variations in phosphor thickness and optical loss, demonstrating the robustness and practical potential of photonic-crystal slab resonance engineering for next-generation display and lighting applications.