Tandem

Together with his collaborators at Helmholtz-Zentrum Berlin and Technical University of Berlin, Dr. Felix Lang from the University of Potsdam previously launched perovskite tandem solar cells into space to test their performance with extreme radiation levels and temperature cycles. Recently, he successfully received the first data from his experiment.

July 9, 2024 was the day of the maiden launch of the new Ariane 6 rocket from Guiana Space Centre by ESA. On-board a satellite was a special solar cell experiment. The satellite itself was successfully released one hour and six minutes after launch. “The solar cells have survived launch and started to produce energy, even without perfect alignment to the sun,” says Felix Lang, who celebrates this first success with his junior research group at the chair of Prof. Dr. Dieter Neher, funded by a Freigeist-Fellowship of the Volkswagen Foundation.

Jiangsu Xiehang Energy Technology (Fellow Energy/Xiehang Energy), a holding company of Turkey’s Chen Solar photovoltaic module and smart device manufacturer, has announced its plan to build a perovskite solar cell and module factory in Sichuan Province, China.

Fellow Energy had negotiated with the local government of Dechang County, Sichuan Province, for the construction of the project. It plans to build a solar cell factory to produce 2GW of perovskite-silicon tandem solar cells and 5GW of high-efficiency solar modules annually upon completion of the facility.

In contrast to conventional (n–i–p) PSCs, inverted (p–i–n) PSCs offer enhanced stability and integrability with tandem solar cell architectures, which have garnered increasing interest. However, p–i–n cells tend to suffer from energy level misalignment with transport layers, imbalanced transport of photo-generated electrons and holes, and significant defects with the perovskite films.

Recently, researchers from King Abdullah University of Science and Technology (KAUST), Newcastle University, National Renewable Energy Laboratory (NREL) and Saudi Aramco Research and Development Center developed a nonionic n-type molecule (tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB) that, through hydrogen bonding and Lewis acid–base reactions with perovskite surfaces or grain boundaries, enables in situ modulation of perovskite energetics, effectively mitigating the key challenges of p–i–n perovskite solar cells (PSCs). 

Scientists at the Fraunhofer Institute for Solar Energy Systems ISE have developed a perovskite silicon tandem solar cell with 31.6% efficiency. 

The new 1 cm² solar cell is special in that the perovskite layer of the top cell was deposited on an industrially textured silicon heterojunction solar cell using a hybrid manufacturing route. The successful use of textured standard silicon solar cells and the uniform application of the perovskite layer on the texturized surface are important prerequisites for the industrial production of perovskite silicon tandem solar cells.

Oxford PV has announced that it has started the commercialization of tandem solar technology with the first shipment to a U.S.-based customer.

The 72-cell panels, comprised of Oxford PV’s proprietary perovskite-on-silicon solar cells, can reportedly produce up to 20% more energy than a standard silicon panel. They will be used in a utility-scale installation, reducing the levelized cost of electricity (LCOE) and contributing to more efficient land use by generating more electricity from the same area.

The close collaboration between researchers at France's National Solar Energy Institute (INES) – a division of the French Alternative Energies and Atomic Energy Commission (CEA) - and 3SUN has reportedly yielded a certified efficiency record for a perovskite-on-silicon tandem photovoltaic cell measuring 9 cm² after shading correction.

The team explained that most of the efficiency records published internationally relate to a surface area of 1 cm². They said that the surface is a real challenge that they are addressing in their developments. This result marks a new stage in the development of PIN-type 2-terminal tandem cells. The progress is evident, with 26.5% in March 2023, then 27.1% in June 2023, 28.4% in December 2023, 28.7% last June and now 29.8%, for devices showing a Voc greater than 1900 mV.

Flexell Space, an in-house venture of Hanwha Systems, has announced that it has signed a letter of intent (LOI) with Airbus Defence and Space GmbH (Airbus) to develop next-generation space solar cell modules using perovskite/CIGS tandem solar cell technology. This collaboration aims to revolutionize the efficiency and weight of space solar cells, marking a significant milestone in the aerospace industry.

Through this agreement, Flexell Space and Airbus plan to design and develop space solar cell modules that are more than half the weight of existing models while maintaining performance and efficiency. By applying Flexell Space's tandem solar cell technology, the new solar cells will aim to offer low cost, high efficiency, rapid production, and flexibility.

Hanwha Q CELLS, according to BusinessKorea, is shifting its strategy from research and development to rapid commercialization in the field of tandem solar cells. This strategic pivot comes, as was reported, as Chinese companies invest heavily in improving tandem energy efficiency.

Hanwha Q CELLS is reportedly set to complete the final inspection of its 40MW perovskite-tandem cell pilot line in Jincheon, Chungbuk, as early as October this year and begin trial operations. The company aims to start commercial production by 2026, believing that entering mass production ahead of China is crucial to gaining the upper hand in the market.

An international team of researchers, including ones from the University of Toronto, University of Toledo, Northwestern University, Lawrence Berkeley National Laboratory, KAUST and more, recently developed an all-perovskite tandem device that is said to show reduced recombination losses in the cell’s bottom device and excellent stability.

Image credit: Northwestern University
 

To improve the perovskite solar cell’s surface, the scientists created partially non-conductive and non-functional areas that protect the perovskite area underneath from becoming defective. The team examined the addition of diamine to improve the perovskite solar cell’s surface. The scientists found that the process made the surface more stable and improved the overall performance, resulting in a power conversion efficiency of 27.4% with better stability.

Researchers from China's Beijing Institute of Technology, Peking University, Central South University, Jiangnan University and Auner Technology have developed a unique binary 2D perovskite passivation approach and used it to fabricate a monolithic perovskite/silicon tandem solar cell with a steady-state efficiency of 30.65% (reportedly assessed by a third party). 

Schematic of the monolithic tandem structure based on a double-side textured silicon heterojunction cell. Image credit: Nature Communications

The tandem devices also retained 96% of their initial efficiency after 527 h of operation under full spectral continuous illumination, and 98% after 1000 h of damp-heat testing (85 °C with 85% relative humidity).