Overcoming the instability of dye-sensitized and perovskite solar cells through biosourced, fluorinated and water-based polymers

Photovoltaic (PV) technology has evolved rapidly in the past few decades and now encompasses a large variety of materials and device structures. A key aspect to be taken into account in any PV technology is the operational durability under real outdoor conditions, as well as the sustainability of materials/components and the facile integration with energy storage systems. In the last five years, dye-sensitized solar cells (DSSCs) with water-based electrolytes are considered as one of the possible breakthroughs towards DSSCs large-scale diffusion. If opportunely developed and optimized, aqueous solar cells can be truly considered a zero-impact photovoltaic device with no toxic components. Moreover, the possibility of gellyfing the electrolyte into a solid matrix can reduce the leakage outside the device, thus increasing the long-term stability. In this respect, cellulosic and - more generally - bio-derived polymers appear promising candidates for electrolyte stabilization, being renewable and easy available at low cost. Moreover, paper-based flexible electrodes and electrolytes for third generation solar cells, useful to lower the oil-derived components and typical high temperatures used during electrodes’ processing, are studied and thoroughly characterized in bendable configurations. Perovskite solar cells are revolutionizing the hybrid photovoltaic scenario, but stability issues still limit their widespread commercial distribution even if an electrolyte (typically the weakest component) is not present. Fluorinated polymers can be designed and functionalized in order to keep perovskite solar cells stable under strong light and humidity levels.