Researchers from China's Shanghai Jiao Tong University, Fujian Science & Technology Innovation Laboratory for Energy Devices of China (CATL 21C Lab) and Shanghai Non-carbon Energy Conversion and Utilization Institute have developed an in situ dual‑interface modification strategy to enhance the performance and durability of large‑area perovskite solar modules.
The team addresses a critical challenge in p–i–n‑type perovskite solar cells: the simultaneous optimization of the two key interfaces - particularly between the perovskite layer and self‑assembled monolayers (SAMs). These interfaces largely determine device efficiency and stability, yet their regulation has remained difficult to achieve in scalable, large‑area module fabrication.
The research team introduced 5‑aminovaleric acid hydroiodide (5AVAI) as a bifunctional molecular interface spacer capable of modifying both interfaces during fabrication - eliminating the need for additional post‑processing steps. The molecule’s carboxyl group anchors it to the SAM layer, improving surface wettability and molecular alignment, while its amino group interacts with the perovskite and transport layers to strengthen interface contacts. During perovskite crystallization, part of the 5AVAI migrates toward the upper surface, effectively passivating defects and relieving lattice strain.
Using this integrated in situ modification approach, the team achieved a power conversion efficiency of 22.31% (certified 21.69%) in 10 cm × 10 cm perovskite modules with an aperture area of 64 cm², fabricated via scalable slot‑die coating. The resulting modules demonstrated exceptional durability, maintaining 95.6% of their initial efficiency after 2000 hours of continuous operation at 75 °C - said to be among the highest operational stabilities reported for large‑area perovskite solar modules.
This work signifies a step toward bridging the efficiency and stability gap between small‑area perovskite solar cells, which now exceed 27% efficiency, and commercially scalable modules. By resolving key limitations in surface wettability, interfacial contact, and lattice strain, the in situ dual‑interface regulation strategy offers a simple, post‑treatment‑free pathway for manufacturing high‑performance, long‑lived perovskite solar technologies.
