Researchers from Zhengzhou University, University of Surrey, Chinese Academy of Sciences, Wuhan University of Technology, University of Cambridge and University of Electronic Science and Technology of China (UESTC) have developed flexible perovskite solar modules (f-PSMs) using single-walled carbon nanotubes (SWCNTs) as window electrodes.
Flexible perovskite solar modules are considered promising for lightweight and sustainable energy generation, but their commercial development has been constrained by limited long-term stability and reliance on indium tin oxide (ITO) electrodes. The research team demonstrated that SWCNT-based electrodes can deliver power conversion efficiencies (PCEs) exceeding 20% at module scale. Further improvement was achieved by treating the SWCNTs with sulfuric acid (H₂SO₄), which enhanced their conductivity and facilitated the formation of a compact NiSO₄–NiOx interface. This interface improves charge transfer between the perovskite absorber and the hole transport layer, enabling ITO-free perovskite solar cells to reach efficiencies above 24% in rigid configurations and about 23% in flexible modules.
These devices retained over 95% of their initial efficiency under conditions such as high temperature, humidity, and continuous illumination for one month. The SWCNT films also exhibited strong mechanical stability, maintaining performance after repeated bending and exposure to conditions simulating day - night cycling. Compared with ITO-based counterparts, SWCNT electrodes offer advantages in flexibility, chemical durability, and cost, providing a more sustainable option for large-scale manufacturing.
In addition, the team demonstrated that the fabrication process is compatible with scalable production techniques, such as chemical vapor deposition (CVD) combined with roll-to-roll coating, enabling the preparation of meter-scale SWCNT films. The study highlights the potential of acid-treated SWCNT electrodes to support efficient, stable, and ITO-free flexible perovskite solar technology suitable for practical applications.
