DFT study of dithiafulvenyl phenothiazine double donor dyes modulated by π-spacer engineering
Year: 2026
Type: article
Abstract: Based on the reference dye WD14 (D–D–A), eleven novel D–D–π–A organic sensitizers (DPT1–DPT11) were designed by systematically introducing π spacers with varied fusion patterns and substituents between the dual donors (dithiafulvenyl and phenothiazine) and the cyanoacrylic acid acceptor. DFT/TD-DFT calculations at the M06-2X/6-311G (d, p) level with IEF-PCM methanol solvation revealed that π spacer incorporation narrows the HOMO-LUMO gap, redshifts absorption, and enhances light-harvesting efficiency. Electron-withdrawing substituents on the π spacer reduce the exciton binding energy and electron reorganization energy, while electron-donating groups lower regeneration free energy ΔG reg . Notably, DPT2 and DPT8 exhibit theoretically favorable properties among the designed dyes, including a redshifted λ max , near-unity LHE, a thermodynamically sufficient electron injection driving force, a relatively high V OC , and low λ total , which collectively suggest their potential as promising candidates for experimental synthesis. All dyes adsorb stably on (TiO 2 ) 16 via bidentate bridging with high adsorption energies, inducing further absorption redshift and interfacial orbital hybridization.
Source: iScience
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,240
OpenAlex ID: W7155004462