Subphthalocyanine Triimides: Solution Processable Bowl-Shaped Acceptors for Bulk Heterojunction Solar Cells

Ten subphthalocyanine triimides (SubPcTI) with different substituents at imide sites and B atoms were designed and synthesized. These compounds with low-lying lowest unoccupied molecular orbital energy levels (from −3.91 to −3.98 eV), strong absorption in the range of 450–650 nm, and adjustable solubility are expected to be excellent electron acceptors. Non-fullerene bulk heterojunction organic solar cells based on acceptor 8c showed power conversion efficiency of 4.92%, which is the highest value among subphthalocyanine derivatives.