Low-temperature liquid-assisted vibrational stress-relief strategy enables stable and efficient perovskite solar cells.

Abstract

The commercialization of perovskite photovoltaics is hindered by intrinsic defects and interfacial strain in polycrystalline films, which compromise both efficiency and stability. Conventional chemical passivation is frequently composition- and structure-dependent and introduces heterogeneous impurities that generate additional stress. Here, we introduce a universal low-temperature liquid-assisted vibrational stress relief (LTL-VSR) strategy that directly addresses the root causes of material degradation through physical acoustic vibration. High-frequency vibrations induce cavitation collapse and resonant lattice sliding, removing nanoscale impurities, annihilating ionic vacancies, and reducing residual stress by over tenfold without thermal damage. This mechanical healing strategy is broadly compatible with diverse perovskite compositions, device architectures, and sizes, delivering power conversion efficiencies (PCEs) of 26.47% for rigid and 24.64% for flexible cells. Moreover, large-area modules achieved PCEs of 23.59% and 20.55% for aperture areas of 16.8 cm² and 600 cm², respectively. Unencapsulated n-i-p devices retain 92.4% of initial efficiency after 1200 hours of operation. The universality and scalability of LTL-VSR position it as a transformative approach for the industrial manufacturing of perovskite photovoltaics.