Stability-enhanced perovskite heterointerfaces and solar cells via strongly anchored and sterically hindered ligands

The inherent dynamic behavior observed in 2D‐3D interfaces in perovskite solar cells (PSC), driven by ion diffusion and migration, poses a significant challenge in establishing a stable passivation and barrier interface that can fulfill the device's complete lifecycle requirements. In this work, we construct large sterically hindered one-dimensional (1D) perovskite crystals integrated with the perovskite surface and observed their evolution during accelerated aging for the first time. The results show that this strong interfacial bonding not only effectively passivates surface defects but also prevents interface reconstruction due to migration, even under elevated temperatures. Moreover, it serving as an effective barrier can significantly suppress the interdiffusion between the copper electrode and the perovskite layer. Resultantly, our approach attained a remarkable efficiency of 23.3% via a scalable coating process in FA0.3MA0.7PbI3 PSC device. Notably, these devices exhibited significantly enhanced operational stability (T95 ≈1200 h, 55 ± 5 °C) and thermal stability (T90 ≈700 h, 85 °C).