Mesoscale Ordering 3D Mosaic Self-Assembly of Dopant-Free Hole Transport Material for Perovskite Solar Cells

To enhance n-i-p perovskite solar cell (PSC) performance, we optimized the hole transport material (HTM) by using a cost-effective N,N′-bicarbazole-based molecule, BCzSPA, with a 3D conjugated extended “L”-type configuration, to fix the molecular packing model and charge hopping channel. By implementing mesoscale molecular tailoring strategies to order the molecular stacking of BCzSPA, we have significantly realized a dense 3D mosaic self-assembly with intermolecular coupling and multichannel charge hopping properties. The proper incorporation of heteroatom-promoted multidirectional molecular interactions and enhanced morphological stability has simultaneously optimized the perovskite/HTM interfacial contact, inhibited defect formation, and further suppressed charge recombination loss. As a result, the resulting PSCs have achieved a promising efficiency of 25.42% (certified PCE, 24.53%) for a small-area (0.1 cm²) device as well as 24.01% for a large-area (1 cm²) device, while demonstrating remarkable stabilities, with T₈₀ lifetimes exceeding 2400 h under operation or thermal aging at 85 °C.