Flexible perovskite solar modules (f-PSMs) are a key innovation in current renewable energy technology, offering a pathway toward sustainable and efficient energy solutions. However, ensuring long-term operational stability without compromising efficiency or increasing material costs remains a critical challenge.
In a new study published in Joule on December 9, a joint research team from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences and Zhengzhou University has achieved power conversion efficiency (PCE) surpassing 20% in flexible modules capable of withstanding a range of external stresses. The study highlights the use of single-walled carbon nanotubes (SWCNTs) as window electrodes for scalable f-PSMs.
SWCNT films exhibit excellent hydrophobicity, resisting moisture-induced degradation while enhancing device stability. Their flexibility and affordability further position SWCNT-based electrodes as a practical option for sustainable energy systems, providing an ideal opportunity for buildings and infrastructure to incorporate their own power sources in support of a net-zero carbon emissions future.
A key advance of this study comes from treating the SWCNT network with H₂SO₄. The researchers discovered that H₂SO₄ not only enhances the conductivity of the SWCNT films but also interacts with NiOx to form a compact NiSO₄–NiOx layer. This interaction further promotes charge transfer between perovskite and the hole transport material, enabling ITO-free perovskite solar cells (PSCs) to reach over 24% PCE, with flexible versions maintaining roughly 23%. These devices maintained over 95% of their original PCEs under various external stresses, including high temperatures, high humidity, and continuous solar irradiation for one month.
The researchers also demonstrated that their straightforward, scalable fabrication method enabled flexible, module-scale, ITO-free devices to achieve over 20% PCE, accompanied by markedly enhanced stability and bendability.
Moreover, SWCNT films can be produced on a meter scale using a CVD-integrated roll-to-roll process, providing a feasible approach to scaling up SWCNT-based modules.
Overall, these findings highlight the performance benefits of SWCNT electrodes treated using conventional acidic methods.
