Carbon nanotubes in hybrid photovoltaics: Dye sensitized and perovskites solar cells

The state-of-the-art in carbon nanotubes (CNTs) hybrid photovoltaics, namely dye-sensitized (DSSCs) and perovskite solar cells (PSC), is comprehensively summarized, highlighting the most relevant achievements compared to other nanocarbons. In particular, the description of the working principles of DSSCs and the typical analysis tools to understand the impact of using CNTs are provided. Moreover, CNTs as an integrative component in DSSCs are reviewed highlighting the implementation routes and the best efficiencies obtained depending on both the integration process and the CNT type. A similar scheme is followed for the description of CNT-based PSCs. Their working mechanism and use of CNTs in each part of the PSC is presented along with the most representative examples so far. Overall, the potential of CNT in photovoltaics is clearly reviewed, giving a comprehensive summary of advances, challenges, and novel concepts that are pursued in this constantly advancing field.