Dielectric-Chemical Interfacial Engineering Toward Improved Efficiency and Reverse-Bias Stability for Air-Processed...

The performance of air-processed perovskite solar cells (PSCs) is often compromised by the vulnerable perovskite/charge transport layer interface arising from exposure to ambient moisture during fabrication, which promotes nonradiative recombination, ion migration, and poor tolerance to reverse-bias stress. Conventional passivation strategies primarily focus on defect-density reduction and fail to address these issues simultaneously. Here, we report a dielectric-chemical interfacial engineering based on solution-processed metal oxide nanoparticles deposited at the perovskite/hole transport layer (HTL) interface. On one hand, the Pb-O coordination between the metal oxide and the perovskite surface chemically passivates Pb-related defects. On the other hand, the resulting high-κ dielectric environment screens residual charged defects and increases interfacial capacitance, thereby suppressing recombination, mitigating electric-field localization under reverse bias, and restraining ion migration. Among the investigated metal oxides, ZrO₂ provides the most effective interfacial passivation and dielectric screening, leading to notable efficiencies of 25.60% and 22.85% for the PSCs and perovskite solar modules (PSMs), respectively. Moreover, the resulting devices exhibit excellent operational robustness, as evidenced by the increased reverse breakdown voltage from -1.8 V to -4.0 V and the retention of 96.8% of the initial efficiency after 1470 h of maximum power point tracking (MPPT) with encapsulation.