Polymer electrolytes and perovskites: lights and shadows in photovoltaic devices

Photoelectrochemical devices for the conversion of sunlight into electricity are experiencing a period of fervour due to the use of new solid-state materials capable of ensuring a durability higher than that of liquid electrolytes-based cells. Dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs) are currently contending for the role of leader in the field of third-generation photovoltaic technologies. In particular, such success is attributed to the introduction of polymer electrolytes and perovskites, which have recently contributed to obtaining high conversion efficiencies. This review summarizes the most important results in this field and the strategies developed to maximize DSSCs and PSCs performance. In addition, limitations and disadvantages of polymer electrolytes and perovskites are presented, together with possible strategies aimed at improving the photovoltaic efficiency, reducing the cost and limiting the use of toxic and rare materials.