Novel Low‐Bandgap Organic Dyads Derived from Diketopyrrolopyrrole for Efficient Single‐Component Organic Solar Cells

In order to attain high performance in single‐component organic solar cells (SCOSCs), it requires the designing of light‐harvesting structures that can absorb light across a wide range from visible to near‐infrared (NIR) wavelengths. In this investigation, two novel dyad materials, denoted as SPS‐BF‐Full and SPS‐BT‐Full are designed and synthesized, consisting of covalently linked benzofuran (BF) and benzothiophene (BT) functionalized thiophene–diketopyrrolopyrrole (TDPP) as donor and N‐methyl fullero[60]pyrrolidine as the acceptor, respectively. The incorporation of a phenyl bridge between TDPP and fullero[60]pyrrolidine enhances light absorption in SPS‐BF‐Full and SPS‐BT‐Full, resulting to a high short‐circuit density ( J SC ). Consequently, the SCOSCs utilizing SPS‐BT‐Full and SPS‐BF‐Full attained overall power conversion efficiency (PCE) of 6.28 and 7.35%, respectively. The high photovoltaic performance of OSCs utilizing SPS‐BF‐Full is mainly attributed to its higher external quantum efficiency and balanced hole and electron mobility ( μ e / μ h = 1.39), along with imporved charge carrier extraction, revealing more effective charge transport in comparison to SPS‐BT‐Full counterparts.