Researchers from  Helmholtz-Zentrum Berlin (HZB) and Humboldt University, Berlin, have announced achieving an efficiency of 24.6% with a copper indium gallium selenide (CIGS)-perovskite tandem cell.

The results were certified by the independent Fraunhofer Institute for Solar Energy Systems.

Researchers developed the tandem solar cell by combining a bottom cell made of CIGS with a top cell based on perovskite.

The perovskite absorber layer was produced in HZB and Humboldt University’s joint laboratory.

Thin-film solar cells require less energy and material to produce, resulting in a smaller environmental footprint. CIGS thin films can be applied to flexible substrates for better performance.

Rutger Schlatmann, Solar Energy Department spokesperson, HZB, said, “With the combination of CIGS-perovskite, we are confident that CIGS-perovskite tandem cells can achieve much higher efficiencies, probably more than 30%.”

In 2024, an international team led by the University of Surrey with Imperial College London also identified a strategy to improve the performance and stability of solar cells made from perovskites by mitigating a previously hidden degradation pathway. In the study published in Energy and Environmental Science, the researchers said they could produce lead-tin perovskite solar cells that reach 23.2% power conversion.

Notably, they were able to design a strategy that they claimed improves the lifetime of these devices by 66%.

Recently, JinkoSolar Holding, a solar module manufacturer based in China, announced that its new N-type tunnel oxide passivated contact (TOPCon)-based perovskite tandem solar cell achieved a conversion efficiency of 33.84%, exceeding its prior record of 33.24%.

This innovative tandem cell technology employs the company’s N-type monocrystalline TOPCon solar cell as the bottom cell. Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences independently tested this claim.

In December last year, China-based solar photovoltaics company Trina Solar announced that its industrial n-type total passivation solar cell, based on heterojunction technology, achieved a front-side efficiency of 27.08%.