Scientists in South Korea have developed an ultra-light and flexible solar cell that has set a new world record for efficiency.
The research team at the Korea Institute of Energy Research (KIER) created a solar cell made from perovskite and CIGS (copper indium gallium selenide) materials.
This new solar cell reached a power conversion efficiency of 23.64%, the highest ever reported for this type of flexible solar technology.
It could be a game-changer for clean energy use in buildings, cars, airplanes, and even satellites.
Traditional solar panels, mostly made from crystalline silicon, are cheap to produce and widely used. However, these single-layer cells are nearing their maximum efficiency, which has led scientists to explore tandem solar cells.
Tandem solar cells combine two different materials to absorb more sunlight and produce more energy.
The most successful so far have been perovskite/silicon combinations, which have reached efficiencies as high as 34.6%.
But there’s a downside—these cells are heavy and fragile, making them unsuitable for many real-world uses.
That’s where the new flexible perovskite/CIGS tandem solar cells come in. CIGS is a thin-film material that is lightweight and bendable, making it ideal for use on curved surfaces like the sides of buildings or the roofs of vehicles.
Until now, these types of cells had lower efficiency and were harder to manufacture.
The KIER team overcame these challenges by creating a new, simpler way to make the cells and by improving their structure.
The team used a clever “lift-off” process. They started by coating a glass sheet with a layer of polyimide—a flexible, heat-resistant material. Then, they built the solar cell on top of that and later peeled it off the glass.
This method allowed them to take advantage of the stability of glass during construction, while still ending up with a flexible final product. The flat glass also made it easier to apply the layers evenly, improving both performance and reliability.
Another breakthrough came from understanding how to reduce tiny defects inside the solar cell. During normal manufacturing, potassium from the glass can leak into the solar cell and create problems that lower efficiency.
The team used computer simulations to show that the polyimide layer could block this potassium from spreading too far. This led to fewer defects and better performance.
To test how tough their solar cells are, the researchers bent them 100,000 times in lab simulations. After all that stress, the solar cells still kept 97.7% of their original power output. This shows they’re not just efficient, but also durable.
Dr. Inyoung Jeong, who led the study, said the achievement shows strong promise for commercial use and brings us closer to solar cells that are not only flexible but could one day reach 30% efficiency.
Dr. Kihwan Kim, another lead researcher, said these solar cells have a power-to-weight ratio about ten times higher than current perovskite/silicon cells, making them especially useful for lightweight solar systems in fields like aerospace and transportation.
The team hopes their technology will support the growth of renewable energy by making solar power more flexible, lighter, and easier to use in a wide range of industries.
