Challenges and Perspectives for an Extended Use of the Dye‐Sensitized Solar Cells

The upcoming generation of photovoltaic (PV) technologies that will support the required energy shift is expected to include the technology of dye-sensitized solar cells (DSSCs), as DSSCs have been recognized as one of the most promising alternatives to silicon-based devices, ensuring good PV efficiency while exploiting sustainable and low-cost materials. DSSCs are photoelectrochemical cells that represent the first example of a hybrid organic–inorganic photovoltaicsystem and, as such, initiated the important research sector of BIPV (building-integrated photovoltaics). Recently, DSSCs have also been proposed as an innovative solution in agrivoltaics and archaeophotovoltaics, since the versatility in the chemistry of DSSC components can impart wavelength selectivity in the photoconversion process, a feature that is almost unique in the PV landscape. DSSCs have also demonstrated the capability to efficiently harvest luminous energy under indoor-light conditions, a characteristic that renders them highly attractive for IoT (Internet of Things) applications and, in the context of agrivoltaics, for operation inside greenhouses. Under diffuse light—typical of indoor illumination with artificial light sources—DSSCs exhibit superior photoconversion performance compared to traditional semiconductor-based PV technologies. This advantageous aspect of DSSCs is due primarily to the mesoporous structure of the photosensitive electrode, which enables omnidirectional light harvesting. The present review focuses on the recent evolution of DSSCs, particularly developments in the design, formulation, and preparation of new redox couples, new types of electrolytes, and organic dye-sensitizers. Finally, this contribution also highlights how the nature of the electrode material affects interfacial charge-transfer properties and how electrode surface engineering is crucial in determining both the efficiency and temporal stability of the resulting DSSC. From a production standpoint, recent research has largely focused on identifying scalable manufacturing methods for obtaining DSSCs with high or wavelength-selective transparency for applications in BIPV, agrivoltaics, archaeophotovoltaics, and smart fenestration.