Solar cell with passivation in the laboratory under simulated sunlight. Credit: Thee Vanichangkul.
A team of scientists has achieved a major breakthrough in solar technology by creating a tandem solar cell with a record efficiency of 25.7%.
The research, led by Dr. Felix Lang from the University of Potsdam, along with Prof. Lei Meng and Prof. Yongfang Li from the Chinese Academy of Sciences, combines two innovative materials—perovskite and organic absorbers—to capture sunlight more effectively.
This new type of solar cell is designed to make better use of sunlight by combining materials that absorb different parts of the light spectrum.
The perovskite layer captures blue and green light, while the organic layer absorbs red and infrared light.
By working together, these layers maximize the energy collected from sunlight.
Traditional solar cells, like those made from silicon or CIGS (copper indium gallium selenide), require high processing temperatures.
This not only increases production costs but also leaves a large carbon footprint.
The new tandem solar cell solves these problems by using materials that can be processed at low temperatures, making them more environmentally friendly.
Dr. Lang explained, “We’ve combined two emerging solar technologies—perovskite and organic materials. Both are lightweight, flexible, and have a low environmental impact.”
Achieving this record efficiency wasn’t easy. The team had to overcome two major challenges.
First, the researchers developed a new type of organic solar material that absorbs even more infrared light than before. This expanded the range of light the tandem cell could capture.
Second, they applied a special “passivation layer” to the perovskite material. This layer reduces defects in the perovskite, which previously caused energy losses. By improving the quality of the perovskite layer, the entire solar cell became more efficient.
The [record-breaking efficiency](https://www.nature.com/articles/s41586-024-08160-y) of 25.7% puts this new tandem solar cell on par with traditional technologies, but with a greener production process.
“This breakthrough shows how combining advanced materials can revolutionize solar energy,” said Lang.
The innovative tandem solar cell could pave the way for cleaner, more efficient solar panels, helping us reduce our reliance on fossil fuels and move toward a sustainable future.