Enhancing the reliability of dyes for color filters through TiO₂ adsorption: comprehensive identification of factors affecting photocatalysis

The reliability of materials used in color filters for CMOS image sensors and TVs is crucial for ensuring high image quality. However, previous studies have revealed shortcomings in the reliability of these materials, especially in terms of thermal and photostability, due to their intrinsic properties. This necessitates the development of novel materials for color filters. Here, we present a novel strategy to improve the reliability of color filters by fabricating a hybrid material in which dye is adsorbed onto TiO2, which is well known to promote the photodegradation of organic materials. We synthesized three dyes - perylene, DPP, and azo-based - and analyzed the photophysical properties and reliability of both the individual compounds and the resulting hybrid materials. The hybrid material incorporating perylene-based dye demonstrated enhanced photostability, whereas those with DPP and azo-based dyes exhibited contrasting outcomes. Our study investigated the impact of the dyes' photophysical properties and the amount of TiO2 on the generation of radicals. Additionally, we conducted a quantitative analysis to explore the influence of radical generation on the photostability of the hybrid materials. Lastly, we observed a significant improvement in the thermal stability of the dyes as the amount of TiO2 increased. Notably, only the perylene-based hybrid material exhibited enhancements in both photostability and thermal stability. Consequently, we determined the optimal dye moiety for a hybrid material and identified the factors influencing photocatalysis, as well as specific factors enhancing the material's reliability.