Advancements in metal-free organic dyes: Achieving over 10% efficiency in DSSCs

In this study, we describe the synthesis and characterization of three newly developed metal-free organic dyes, denoted as MRS-1-3. These dyes have been specifically designed and investigated as potential sensitizers for Dye sensitized solar cells (DSSCs). The sensitizers under consideration consist of pyrene units that function as effective electron donors, whereas furan moieties serve as π-spacers. MRS-1-3 was synthesized by including electron acceptor groups, such as cyanonitroacetonitrile, 4-nitrocyanoacetamide, and dicyanovinyl. In this study, a thorough examination was conducted to assess the individual performances of several sensitizers. The results revealed that MRS-3, characterized by a furan π-bridge and dicyanovinyl acceptor group, had the best power conversion efficiency (PCE) of 8.77%. This PCE value surpassed that of N-719, which was determined to be 7.37 %. To enhance the efficacy of MRS-3, an investigation was conducted to assess the impact of co-adsorption using an unidentified co-adsorbent, chenodeoxycholic acid (CDCA), and to compare its performance with that of 2-(p-carboxybenzylidene)-2-cyano-p-(diethylamino)acetanilide (SA-10) synthesized in a previous study. Notably, MRS-3's power conversion efficiency (PCE) went up significantly after co-adsorption with CDCA, reaching 8.83%. Furthermore, the substitution of CDCA with the co-adsorbent SA-10 resulted in enhanced performance of the MRS-3 organic dyes in terms of key parameters such as Jsc (short-circuit current density), Voc (open-circuit voltage), and PCE (Jsc = 21.50 mA cm−2, Voc = 0.750 eV; PCE = 10.15 %). A system composed of MRS-3 and SA-10 exhibits exceptional performance, making it a suitable option for creating highly effective DSSCs. The results of this study provide a valuable contribution to the development of new sensitizers that can be used in future photovoltaic applications. These findings present excellent prospects for improving the efficiencies of solar cells.