Simple Is Best: A p-Phenylene Bridging Methoxydiphenylamine-Substituted Carbazole Hole Transporter for High-Performance Perovskite Solar Cells

Methoxydiphenylamine-substituted carbazole (MODPACz) is widely used to construct hole-transporting materials (HTMs) for perovskite solar cells (PSCs), whose performances rely highly on the linking way of the MODPACz units and the simplicity of the π-bridge. In this paper, we report a new HTM, pPh-2MODPACz, using one of the simplest π-bridges p-phenylene to link the MODPACz units. The structural feature endows pPh-2MODPACz with high hole mobility and conductivity, efficient hole extraction ability, and good film-forming property. MAPbI3-based PSCs using doped and undoped pPh-2MODPACz as the HTM offer efficiencies of ∼20% and 16.07%, respectively; both are better than those of the devices with spiro-OMeTAD as the HTM. The device stability of pPh-2MODPACz-based PSCs is also greatly enhanced. This work demonstrates that the simplest p-phenylene bridge for linking MODPACz can derive a promising HTM with a high device performance, providing a distinctive pathway to develop new HTMs.