Diketopyrrolopyrrole-based single molecules in photovoltaic technologies

The increasing demand for efficient energy sources has led to the emergence of photovoltaic (PV) technologies. However, there remains a need to move them from the laboratory scale to the general market, which requires exceptional materials that provide both stability and efficiency. Among the materials currently being investigated, diketopyrrolopyrroles (DPPs) stand out due to their chemical versatility, robustness, and optoelectronic properties, especially their intense absorption in the visible and near infrared spectrum, high charge carrier mobility in conjugated systems, good crystallinity and, sometimes, low production costs. In this article, we review the most successful DPP-based single molecules applied in emerging PV technologies to date. Thus, DPP single molecules applied in organic solar cells, dye-sensitized solar cells and perovskite solar cells are presented, together with their chemical structures, photovoltaic device performance and additional information. In addition, we attempt to give some pointers for the optimization of future, DPP-containing molecular designs and to highlight the potential of these building blocks.