Topology Engineering of Heteroatom-Embedded Xanthones as Hole Conductors for Efficient and Stable Air-Processed Perovskite Solar Cells

Organic semiconductors that simultaneously optimize electronic and structural chemical properties are essential for perovskite solar cells (PSCs), yet the design principles enabling such a dual optimization remain poorly understood. Here, we develop topology engineering by embedding carbonyl groups into different molecular scaffolds and synthesize a family of hole conductors (ZW1-ZW3). Topology engineering endows the three molecules with externally positioned or sterically hindered carbonyls, leading to different molecular conformations and electronic properties. Among them, enabled by the large dipole moment, favorable energy levels, edge-on molecular packing, and strengthened interfacial bonding, ZW3 yields outstanding device performance both as a dopant-free hole conductor and as an interfacial modifier, achieving efficiencies of 23.0% and 25.1%, respectively. Particularly, dopant-free ZW3-based PSCs retain 85% of their initial efficiency under maximum power point for 1000 h ( T 80 > 1380 h). This work establishes a molecular design principle of carbonyl topology engineering for organic hole conductors.