A study on red cyanine dyes employing bis(fluorosulfonyl)imide anions for color filters of virtual and augmented reality displays

Abstract

Novel cyanine dyes were designed and synthesized for use in high-resolution OLED red color filters suitable for virtual/augmented reality applications. To enhance stability and solubility in organic solvents, four different weakly coordinating bis(fluorosulfonyl)imide anions were introduced to the cyanine moiety. Additionally, to prevent dye leaching during etching, a substituent containing a methacrylate group was incorporated into the cyanine dye. The spectral properties, solubility in industrial solvents, and stability of the synthesized dyes were investigated to evaluate the dyes for dye-based color filters. Subsequently, spin-coated color filters were fabricated using the optimized photoresists containing the synthesized dyes. The transmittance, chromaticity, and stability of the fabricated color filters were examined. The dyes showed sufficient optical properties and improved solubility in industrial solvents because of their weakly coordinating counter anions. Additionally, the synthesized dyes and prepared color filters exhibited sufficient thermal stability for applications. Furthermore, the prepared color filters exhibited superior transmittances compared to those of their parent dyes.