Record efficiency achieved with perovskite and organic tandem solar cells
Researchers from the University of Potsdam have unveiled a tandem solar cell that combines perovskite and organic materials, setting a new efficiency benchmark of 25.7%. This advancement uses low-temperature processing methods to reduce the carbon footprint while maximizing energy absorption across the entire solar spectrum.
The new solar cell uses two materials that absorb different parts of sunlight: perovskites capture blue and green wavelengths, while a new organic layer focuses on red and infrared wavelengths. These tandem designs optimize the use of sunlight for higher efficiency compared to traditional technologies such as silicon or copper indium gallium selenide (CIGS), which require high-temperature processing and have a greater environmental impact.
Felix Lang, lead researcher on the project, explained that achieving this efficiency required two key innovations. “This was only possible by combining two major breakthroughs,” Lang said. The first was the development of an organic solar cell by Meng and Li, which expanded infrared absorption capabilities. “Yet, tandem solar cells were limited by the perovskite layer, which exhibits strong efficiency losses when adjusted to absorb only blue/green parts of the solar spectrum,” Lang explains.
To overcome this, the team applied a new passivation layer to the perovskite. This isomeric diammonium passivation layer addresses material defects, significantly improving the overall performance of the tandem cell.
The study, entitled “Isomeric diammonium passivation for perovskite-organic tandem solar cells”, has now been published in *Nature*.
