Flexible perovskite solar cells provide lightweight, low-cost energy options but face lower efficiency than rigid versions, mainly due to difficulties in forming uniform films on flexible substrates, especially in large modules.
Researchers from Nanjing University, University of Victoria and Renshine Solar have developed a scalable fabrication strategy based on retreating the wet perovskite films with an in situ additive coating under continuous gas quenching. This method enables dynamic additive modulation during crystallization, unlocking interfacial and bulk film control that is otherwise inaccessible in after-coating treatments or ink modification strategies.
In their recent work, the scientists used this method to create 30 × 40 cm2 wide-bandgap perovskite films on polyethylene terephthalate substrate fabricated under ambient conditions with exceptional crystallinity, low-trap-density and void-free buried interfaces.
As a result, they achieved a PCE of 27.5% for a flexible all-perovskite tandem solar cell (area 0.049 cm2) and a certified 23.0% for a large flexible module (area 20.26 cm2) with a geometric fill factor of 95.8%.
They also demonstrated industrial scalability by slot-die coating a flexible wide-bandgap perovskite module with an aperture area of ~804 cm2 under ambient conditions. These modules retained 97.2% of their initial PCE after 10,000 bending cycles at a 10 mm radius (1% strain) and withstood thermal cycling (−40 °C ↔ 85 °C) and continuous 1-sun illumination.
This work could help narrow the efficiency gap between flexible and rigid perovskite tandems and establishe a practical route towards scalable, high-performance flexible photovoltaics.
