Ladder-type dihydronaphtho[1,2,3,4-rst]pentaphene as building block to construct hole-transporting materials for perovskite solar cells

The stability and photovoltaic performance of perovskite solar cells (PSCs) are greatly affected by the use of hole-transporting materials (HTMs). Polycyclic aromatic hydrocarbons (PAHs) are known for their planar structures, which facilitate efficient charge transport and intermolecular interactions, resulting they possess unique electronic and optical properties. In this study, we describe the synthesis of three D‒π‒D type PAHs-based HTMs compounds (DC-1, DC-2, and DC-3) that contain dihydronaphtho[1,2,3,4-rst]pentaphene (DHNP) as a π conjugation bridge, p-methoxy group-substituted arylamine, and diphenylamine-substituted carbazole groups as the donor groups. These DHNP-based molecules can be used as hole-transporting materials in PSCs due to their favorable frontier molecular orbitals (HOMO/LUMO) energy levels. The PSC devices fabricated with DC-1 yielded a highly efficient power conversion efficiency (PCE) of 18.09%, outperforming those based on DC-2 (13.21%) and DC-3 (14.91%), and slightly higher than those using control spiro-OMeTAD (16.93%). The proposed novel D‒π‒D molecules demonstrate potential as HTMs with promising performance for PSCs and contribute to the development of high-efficiency perovskite solar cells.