The aim of the project is the development of abundant metal-based light-responsive complexes and their use in DSSCs (Dye-sensitized Solar Cells). Several noble metal complexes (Ru, Ir, Pt) have long been considered as lead compounds due to their ideal photophysical and geometrical properties with power conversion efficiency (PCE) values in the 9-11 % range. Despite these ideal photophysical properties, ruthenium is a scarce metal, toxic and expensive and limits the real-world industrial development of the cells. In consequence, the main goal of our project is the replacement of such expensive metals by cheap and environmentally benign metals in the search for developing low-cost efficient devices, and resource-preserving industrial processes.

The L2CM has recently contributed to the field by investigating different approaches to tune the electronic properties of abundant organoferrous complexes (ANR PhotIron). By combination of chemical synthesis and quantum simulations, the parameters influencing the excited state lifetime of organo-ferrous dyes and their interfacial behaviour after chemisorption on semiconductor have been pointed out. The L2CM and the University of Ferrara in Italy (S. Caramori) are currently leaders in the field of iron-sensitized DSSC cells with a record efficiency of 2% very recently obtained.

In spite of these promising results, the efficiency of the Fe-sensitized DSSCs is still to be improved. In this regard, dye-TiO2 interfacial TD-DFT computations have already shed light on the reasons for such limited performance. Therefore, current synthetic efforts are targeted to overcome these specific aspects with the aim to make organoferrous complexes a genuinely alternative to their ruthenium counterparts.

Project: Photothermal therapy (PTT) has garnered increasing interest as a potential alternative to conventional therapeutic methods. This technique utilizes molecules or nanoparticles capable of efficiently converting light into heat. Highly challenging research aspects in the field concern the development of fully organic agents with high biosafety, light absorption in the 700-900 nm biologically transparent window, and that provide efficient PTT effect combined with photoacoustic image-guiding strategy. The CD-Mix project aims to investigate the use of cyanine polymer-conjugates for the fabrication of core-cross-linked micelles though the self-assembly of conjugates followed by dimerization of cyanine dyes within micelles, ultimately facilitating image-guided PTT applications.