Azulene–BODIPY Hybrid Dyes as Non‐Emissive, Wide‐Gamut RGB Colorants for High‐Resolution Color Filters

ABSTRACT The pursuit of high‐performance color filters (CFs) for next‐generation displays demands organic dyes with a wide color gamut, high color purity, low emissivity, and excellent processability. Herein, we report a rational molecular design strategy by integrating the nonalternant, polar azulene unit into the BODIPY scaffold to create three novel derivatives—AzBdpy‐B, AzBdpy‐G, and AzBdpy‐R—tailored for blue, green, and red subpixel applications. By strategically varying the linkage sites (azulene 1‐/2‐positons to BODIPY α / β positions), we precisely modulate intramolecular charge transfer (ICT) strength and frontier molecular orbital hybridization. This achieves targeted absorption peaks at 621 nm (AzBdpy‐B), 735 nm (AzBdpy‐G), and 535 nm (AzBdpy‐R), respectively. The incorporation of azulene not only enables broad spectral tunability but also effectively suppresses radiative decay, resulting in near‐zero visible fluorescence—critical for minimizing background luminance in CFs. CFs fabricated from these materials demonstrate good photothermal stability (Δ E ab < 3 after 150°C heating and UV exposure), high color purity, and wide sRGB coverage (81%), with photolithographic resolution down to 8.2–10.7 µm. Combined experimental and theoretical analyses—including single‐crystal X‐ray diffraction, hole‐electron distribution, and Independent Gradient Model (IGM)—reveal how azulene–BODIPY electronic coupling governs both optical performance and structural robustness. This work establishes azulene‐functionalized BODIPYs as a promising platform for high‐resolution, low‐emissivity RGB color photoresists, offering new insights into the molecular engineering of advanced dye‐based optoelectronic materials.