Synthesis and characterization of thermally stable dyes with improved optical properties for dye-based LCD color filters

Abstract

We have designed and synthesized six phthalocyanine dyes and one benzoperylene dye for dye-based green Liquid Crystal Display (LCD) color filters. The solubility, spectral properties and thermal stability of the prepared six phthalocyanine dyes varied depending on their isomeric structures and core metals. They were dissolved in industrial solvent–binder composites and spin coated with and without yellow compensating benzoperylene dye into dye-based LCD color filters. The prepared color filters exhibited superior optical properties compared to conventional pigment-based ones due to the fluorescence of benzoperylene dye and less light scattering resulting from the smaller particle size of the dyes. The phthalocyanine dyes substituted at the peripheral (β) positions showed enough thermal stability for color filters and the yellow benzoperylene dye effectively compensated the spectra for vivid green colors.