Strain Minimization via Dimyristoylphosphatidylcholine Modification for Perovskite Solar Cells

Abstract

The stability of perovskite solar cells (PSCs) remains a major challenge, primarily due to strain-driven lattice degradation. Here, we introduce a strain minimization strategy using phosphatidylcholine to regulate the strain of perovskite films. We identify linear-shaped dimyristoylphosphatidylcholine (DMPC) as an ideal additive through dynamic stress relaxation within the perovskite lattice, minimizing the deformation ratio by 17-fold (from 0.34 to 0.02%) and increasing the ion-migration activation energy from 0.55 to 0.87 eV. Additionally, DMPC forms robust interfacial bonds with the perovskite, directing crystal growth and improving optoelectronic quality. As a result, DMPC-modified PSCs achieve a champion power conversion efficiency (PCE) of 26.61% and retain 91% of their initial efficiency after 300 temperature cycles (–40 to +85 °C), representing a 15-fold enhancement in T90 lifetime compared to control devices. This work establishes molecular-level strain engineering as an effective route to mitigate lattice stress and deliver thermally durable, high-efficiency perovskite photovoltaics.