Risen claims 30.99% efficiency for perovskite-silicon tandem solar cell

The result was confirmed by China’s National Solar Photovoltaic Product Quality Supervision and Inspection Center. The tandem device is relying on a bottom cell based on a heterojunction design.

Risen Solar announced it achieved a 30.99% power conversion efficiency for a tandem solar cell relying on a top perovskite cell and a bottom silicon heterojunction (HJT) device.

China’s National Solar Photovoltaic Product Quality Supervision and Inspection Center has certified the results.

“We achieved this milestone with a 10 mm x 10 mm cell size,” a spokesperson from the company told pv magazine.

Yang Bochuan, Director of Risen Solar’s Global Photovoltaic Research Institute, highlighted that HJT cells, with their unique structural advantages, are considered the ultimate choice among single p/n junction technologies for future solar cell development. “This advantage is even more pronounced in the realm of perovskite-silicon tandem cells,” he stated.

Heterojunction cells use indium tin oxide (ITO) as a transparent conductive layer, while other cells like BC, TOPCon, and PERC rely on insulating layers. This design allows for easier integration of tandem cells, enhancing overall performance, according to Risen, which also claims that other silicon-based cells, which lack ITO films, require entirely new structural designs for tandem technology, increasing both costs and complexity.

Risen Solar has set ambitious goals for the future. By the end of 2025, the company plans to increase the efficiency of its HJT cells to 26.8% and boost module power to 740 W. Following this achievement, the company aims to further increase power output to 760 W.

The company is also preparing for the commercialization of tandem cells by 2027, targeting a module efficiency exceeding 30% and an output of over 850W.