Selenium: A Unique Member in the Chalcogen Family for Conjugated Materials Used in Perovskite and Organic Solar Cells

Organic conjugated materials play an extremely important role in the development of perovskite and organic solar cells (PVSCs and OSCs). Among different molecular design strategies, the introduction of selenium is an efficient way to optimize material properties and improve the performance of solar cells. The benefits can be attributed to the looser electron cloud delocalization and more polarizable nature of selenium, which help enable stronger intermolecular Se···Se interaction and extended conjugation length, leading to enhanced charge carrier mobility and redshifted absorption in selenium‐incorporated organic conjugated materials. Herein, the design of the selenium‐incorporated materials applied in the PVSCs and OSCs to provide a systematic study on the relationship between chemical structures, material properties, and device performance is focused on. The future direction for further development of selenium‐incorporated organic conjugated materials is also provided.