A quantum chemical study: thoughtful exploration for optimal donors in Y-type dual donor-based dye sensitizers

Abstract

This research explores the influence of different dual donors on the effectiveness of dye sensitizers. We selected 35 diverse donors to construct Y-type dual donor-based dyes, connecting them with thiophene as the π-spacer and cyanoacrylic acid as the acceptor. Density functional theory calculations indicate that these dual donor-based dyes exhibit superior optoelectronic properties compared to their single donor counterparts. Notably, significant variations in charge distribution among the different dual donors affect their donor capabilities. Our calculations specifically highlight the enhanced thermodynamic parameters, including light harvesting efficiency (LHE), the free energy of dye injection (ΔG_inject), and regeneration (ΔG_reg), for donor moieties containing nitrogen atoms, such as NS-3 (N,N-dimethylaniline), NS-5 (diphenylamine), NS-6 (triphenylamine), and NS-8 (4-methoxy-N-(4-methoxyphenyl)-N-phenylaniline). These results suggest that nitrogen-containing donor moieties act as promising candidates for donors for efficient dye sensitizers. However, further experimental validation in the near future will be necessary to confirm our findings.