Synthesis of Tailored Organic Dyes for Specific Applications in Dye-Sensitized PV Cells

Highly conjugated organic compounds play a pivotal role in new technologies for light energy utilization, in which they can perform several different functions. Recently, our group has reported the synthesis and application of organic compounds in various devices for light energy conversion, including their use as sensitizers in PEC cells for solar H2 production,1 hole-transporting layers in perovskite solar cells2 and fluorescent emitters in luminescent solar concentrators.3 In this context, the use of organic dyes as sensitizers in Dye-Sensitized Solar Cells (DSSC, Figure 1a) for electricity production is also a subject of continuing interest by scientists. Among relevant current research topics, we focused on the implementation of advanced molecular design strategies to enhance light harvesting, for example by exploiting Förster Resonance Energy Transfer (FRET, Figure 1b),4 as well as on the development of sensitizers tailored to absorb indoor and diffuse light (Figure 1c), thus opening the way to the use of DSSCs for Internet-of-Things (IoT) applications. In this communication, we will illustrate the principles guiding the design of the new sensitizers, and the methods employed for their synthesis. Their conjugated structures were assembled by using both cross-coupling reactions and direct C-H arylation protocols, as well as specific cyclization procedures. The influence of their structures and spectroelectrochemical properties on device efficiencies will also be briefly discussed. Acknowledgments: We thank the Research Fund for the Italian Electrical System, P -2027, D. M. 388 of 06/11/2024, for financial support.