Enhanced Optical and Thermal Properties of a Novel Yellow Quinophthalone Derivative for Color Filter Colorants in Image Sensors

Herein, the design and synthesis of novel yellow quinophthalone derivatives, 4,5,6,7-tetrachloro-2-(6-chloro-2-(3-hydroxy-1-oxo-1H-cyclopenta[b]naphthalen-2-yl)quinolin-4-yl)isoindoline-1,3-dione (pC-QP) and 4,5,6,7-tetrachloro-2-(7-chloro-2-(3-hydroxy-1-oxo-1H-cyclopenta[b]naphthalen-2-yl)quinolin-4-yl)isoindoline-1,3-dione (mC-QP), are used for use as yellow colorants in image sensors. The synthesized compounds are designed to modulate the optical properties based on the substituted positions of the chloride group within the quinophthalone structure. The solubility of pC-QP and mC-QP in propylene glycol monomethyl ether acetate solvent is found to be 0.08 and 0.15 wt%, respectively. The molar extinction coefficient values of pC-QP and mC-QP in solution are determined to be 3.14 × 10⁴ and 3.62 × 10⁵ L mol⁻¹ cm⁻¹, respectively. The transmittance of mC-QP meets commercial requirements, exhibiting less than 0.3% between 412 and 475 nm and over 91% above 530 nm. Both pC-QP and mC-QP demonstrate high thermal stability with decomposition temperatures of 464 and 393 °C, respectively. As a result, mC-QP emerges as an excellent candidate material for use as a yellow colorant in image sensors due to its outstanding properties.