Scientists at Åbo Akademi University have achieved what many thought impossible: organic solar cells that remain stable and highly efficient for more than 16 years. The discovery, published January 9 in Nature Photonics, marks a significant step toward making flexible, lightweight solar panels a practical reality for everyday use.
The research team developed a novel protective layer that not only shields the solar cells from degradation but also pushes their efficiency to record levels. Their cells achieved an outstanding 18.49% efficiency on small surfaces and maintained 18.06% efficiency even when scaled up to larger areas – a feat that has eluded researchers until now.
Breaking the Stability Barrier
The key innovation lies in the development of a protective layer just 2 nanometers thick – about 50,000 times thinner than a human hair. This ultra-thin shield, made from silicon oxynitride (SiOxNy), protects the delicate organic materials underneath while simultaneously improving their performance.
“The work identified a previously unknown loss mechanism in organic solar cells and a way to overcome it,” notes Ronald Österbacka, one of the study’s lead researchers. By applying this protective layer, the team eliminated a longstanding problem where defects in the solar cell’s bottom contact layer would trap and waste incoming light.
Setting New Records
When subjected to continuous illumination testing, the protected solar cells retained 94% of their initial performance after 2,000 hours of operation. Based on these results, the researchers estimate their cells would maintain 80% of their original efficiency for 24,700 hours of use – equivalent to more than 16 years of real-world operation.
This longevity represents a dramatic improvement over previous organic solar cells, which typically degraded much more quickly. The combination of high efficiency and extended lifespan brings these flexible solar cells much closer to practical commercial use.
From Lab to Market
The discovery’s significance extends beyond just breaking records. Organic photovoltaics are particularly promising for commercial applications because they’re lightweight, flexible, and can be manufactured through energy-efficient processes. Until now, their susceptibility to degradation when exposed to sunlight and air has held back widespread adoption.
The research team, which included collaborators from the Suzhou Institute for Nano-Tech and Nano-Bionics, demonstrated that their breakthrough works not just in small laboratory samples but also in larger panels measuring 1 square centimeter – a critical step toward real-world applications.
Looking Ahead
The implications of this research extend far beyond the laboratory. The protective layer can be applied using simple solution-based methods compatible with large-scale manufacturing, making it a practical option for commercial production.
As the world seeks sustainable energy solutions, these more durable organic solar cells could open new possibilities for integrating solar power into buildings, vehicles, and portable devices where traditional rigid solar panels aren’t practical.