Direction Modulation of Intramolecular Electric Field Boosts Hole Transport in Phthalocyanines for Perovskite Solar Cells

Tuning the strength of intramolecular electric field (IEF) in conjugated molecules has emerged as an effective approach to boost charge transfer. While direction manipulation of IEF would be a potential way that is still unclear. Here, we leverage the control of peripheral substituents of conjugated phthalocyanines to chemically tune the spatial orientation of IEF. By analyzing the spatial swing of side chains using the Kolmogorov-Arnold representation and least squares algorithm, a comprehensive mathematical-physical model has been established. This model enables rapid evaluation of the IEF and maximum hole transport performance induced by spatial swings. The champion phthalocyanine as dopant-free hole transport material in perovskite solar cell realizes a record performance of 23.41 %. Greatly device stability is also exhibited. This work affords a new way to enhance hole transport capabilities of conjugated molecules by optimizing their IEF vector for photovoltaic devices.