Tandem

Semi-transparent solar cells are appealing for many different applications such as building-integrated photovoltaics (BIPVs), tandem solar cells and in wearable electronics. Perovskites could be ideal for semi-transparent applications as they are versatile and easy to optimize.

Semi-transparent perovskite solar cells (ST-PSCs) must try to maximize efficiency and transparency. Methods such as bandgap engineering, thinning perovskite layers, and creating discontinuous structures are being developed to improve their performance. However, challenges still remain with ST-PSC development, such as phase stability and defect management.

Researchers from King Abdullah University of Science and Technology (KAUST) and  Helmholtz-Zentrum Berlin (HZB) have developed a perovskite-silicon tandem solar cell that achieves efficient charge extraction and interface passivation. The team improved the performance of blade-coated tandems by introducing 2D perovskite layers at the bottom interface. 

Image credit: Joule

These modifications enhanced the blade-coated tandem performance to a certified PCE of 31.2%, owing to efficient charge extraction and interface passivation. This work demonstrates the efficiency potential for scalable ink-based fabrication, emphasizing stability and manufacturability, which are crucial for the widespread adoption and commercial success of this promising photovoltaic (PV) technology.

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.