## 4 Conclusions  
New blue colorant compounds, BAPCP and HAPCP, were successfully synthesized as color filter materials for image sensors. The material developed in this study was assessed for its applicability to color filters by focusing on a comparison of its optical and thermal stability characteristics with those of the commercially available Disperse Blue 359. Furthermore, CV measurements were conducted to indirectly evaluate its photochemical stability. Future work will address photostability and chemical stability in detail, with plans to report the results in forthcoming studies. These molecules were designed to control molecular aggregation by incorporating a pyrrole group into the core structure and introducing cyano groups and amino alkyl groups, which enhanced optical properties during film formation. BAPCP exhibited a solubility of 1.3 wt% in PGMEA, and its optical properties, such as maximum absorption wavelength and transmittance in solution, were found to be comparable to or superior to those of the commercial blue material, Disperse Blue 359. In particular, the molar extinction coefficient of BAPCP in solution was 4.5 times higher than that of Disperse Blue 359. In thermal stability evaluations, BAPCP exhibited excellent thermal stability, with almost no change before and after heat treatment. The compounds demonstrated high inherent thermal stability, with a T\({}_{\text{d}}\) exceeding 279 \({}^{\circ}\)C. Because of its superior absorption, transmittance, and thermal stability, BAPCP is expected to have potential for future applications. These results suggest that BAPCP holds promise as a next-generation material candidate not only for image sensors but also for a variety of organic displays and semiconductor fields.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app15020799/s1](https://www.mdpi.com/article/10.3390/app15020799/s1)]([https://www.mdpi.com/article/10.3390/app15020799/s1](https://www.mdpi.com/article/10.3390/app15020799/s1)), Figure S1: Pictures of synthesized compounds (a) BAPCP and (b) HAPCP; Figure S2: \({}^{1}\)H NMR spectrum of BAPCP; Figure S3: \({}^{13}\)C NMR spectrum of BAPCP; Figure S4: \({}^{1}\)H NMR spectrum of HAPCP; Figure S5: \({}^{13}\)C NMR spectrum of HAPCP; Figure S6: FTIR spectra of (a) BAPCP and (b) HAPCP; Figure S7: Absorbance at 615 nm as a function of concentration for determining the molar extinction coefficient of the synthesized materials, measured with a 0.5 cm path length cell: (a) BAPCP and (b) HAPCP; Figure S8: Mass spectrum of BAPCP; Figure S9: Mass spectrum of HAPCP; Table S1: Geometry optimizations in Cartesian coordinates of (a) Disperse Blue 359, (b) BAPCP, and (c) HAPCP.  
Conceptualization, S.P. (Sunwoo Park), H.K., C.Y. and J.P.; methodology, H.K. and C.Y.; validation, C.Y., H.L. and J.P.; formal analysis, S.P. (Sunwoo Park), S.P. (Sangwook Park) and K.L.; investigation, S.P. (Sangwook Park) and S.O.; resources, J.P.; writing--original draft preparation, S.P. (Sunwoo Park), H.L. and J.P.; writing--review and editing, S.P. (Sunwoo Park), H.L. and J.P.; visualization, S.P. (Sunwoo Park), S.P. (Sangwook Park) and S.O.; supervision, J.P.; project administration, J.P.; funding acquisition, J.P. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2020R1A6A1A03048004). This work was partly supported by the GRRC program of Gyeonggi province (GRRCKYUNGHE2023-B01, Development of ultra-fine process materials based on the sub-nanometer class for the next-generation semiconductors).  
Not applicable.  
The data are contained within the article and Supplementary Materials.  
The authors declare no conflicts of interest.