Innovative approaches toward fully sustainable Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs), have been thoroughly and extensively investigated in the last three decades, as a really promising emerging photovoltaic technology. Since their first appearance in 1991, DSSCs have gained increasing attention and have been classified as feasible alternatives to conventional photovoltaic devices due to their numerous advantages, such as cheap and simple preparation methods, the possibility of being integrated in buildings and astonishing performances under indoor and diffuse illumination conditions. Photoconversion efficiencies of up to 14% and 8% have been obtained for lab-scale devices and modules, respectively, under full illumination. Albeit the efforts made, these values seem arduous to be outdone. Nevertheless, recent lab-scale systems have demonstrated photoconversion efficiencies of up to 33% under indoor illumination (i.e. 1000 lux) leading to an actual Renaissance (or Revival) of these devices. It is worth mentioning that scientists in this field are developing innovative materials aiming at long-term and efficient devices, being the concept of sustainability often set apart. However, in light of effective commercialization of this technology, stability, efficiency and sustainability should be considered as the essential keywords beside efficiency. Indeed, nowadays, DSSCs are finding their “new way back” towards sustainability and a huge number of reports focused on the preparation of green and cost-effective materials to replace the standard ones. The present contribution aims to (i) give an overview of the most adopted strategies to enhance the sustainability of materials in classical DSSC components (i.e. sensitizer, redox couple, electrolyte and counter-electrode), including smart synthesis and deposition procedures and (ii) to stress the utmost importance of this concept in the design of the next generation of DSSC materials.