Tuning the visible-NIR absorption of azulenocyanine-based photosensitizers

• Published in: Journal of molecular modeling 2022-11, Vol.28 (11), p.344-344, Article 344
• Main Authors: Granados-Tavera, Kevin, Zambrano-Angulo, Michael, Hidalgo-Rosa, Yoan, Zarate, Ximena, Cárdenas-Jirón, Gloria
• Format: Article
• Language: English
• Subjects: Absorption; Adsorption; Anatase; Characterization and Evaluation of Materials; Charge transfer; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Density functional theory; Dyes; Electrons; Error correction; Mathematical analysis; Molecular Medicine; Original Paper; Photoelectricity; Solar energy conversion; Theoretical and Computational Chemistry; Titanium dioxide; XXI-Brazilian Symposium of Theoretical Chemistry (SBQT2021)
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-022-05329-y

A new photosensitizer 1-WS55 (dyad) based on two dyes with excellent properties, azulenocyanine ( 1 ) and WS55 , is proposed at the density functional theory level (M06/def2-SVP). 1 is a dye having a broad NIR absorption (~ 1000 nm), and WS55 is a metal-free organic dye that presents a huge photoelectric conversion efficiency (PCE) of 9.5%. The dyad presents a panchromatic absorption along the UV–Vis-NIR region. It exhibits two intense Q bands (880, 926 nm) in the NIR region, one strong band (672 nm) in the visible region, and several bands in 300–600 nm. Charge transfer bands in the dyad from 1 to WS55 were found in the visible region, which favors the adsorption on an anatase TiO 2 surface. The interaction energies dyad (dye)-TiO 2 were calculated as a periodic system and corrected by the basis set superposition error. These show better adsorption for the dyad than fragments 1 and WS55 . The electron injection calculated from the dye (dyad) to TiO 2 suggests an efficient solar energy conversion because of ΔG inj  > 0.2 eV. Additionally, calculations performed for the reorganization energy of electrons and holes indicate that the dyad presents the highest charge mobility. In summary, the dyad proposed 1-WS55 constitutes an excellent candidate to be used as a potential photosensitizer for the DSSCs. Graphical abstract