Tandem

GCL Technology, one of China’s largest solar panel materials producers, will reportedly invest 700 million yuan (almost USD$98 million) to transition to a more lucrative next-generation technology, as the industry grapples with losses and oversupply.

The Hong Kong-listed company aims to complete the first phase of a 500 megawatt (MW) plant in Kunshan by the middle of next year, for solar modules that combine cells stacked with perovskite and crystalline silicon, according to a statement by Fan Bin, chairman of GCL Perovskite. “The value of the [nascent] perovskite technology lies in the ample room for uplifting its energy conversion efficiency,” he said. “That is why manufacturers are willing to invest in its development.” The future cost of production using the perovskite-silicon technology could be lower than the crystalline silicon technology, he added.

Researchers from King Abdullah University of Science and Technology (KAUST) and Marmara University set out to minimize crystal defects and film inhomogeneities in perovskite top cells, to achieve the full potential of monolithic perovskite/silicon tandem solar cells. 

In their recent work, the scientists discuss the use of methylenediammonium dichloride as an additive to the perovskite precursor solution, resulting in the incorporation of in situ–formed tetrahydrotriazinium (THTZ-H⁺) into the perovskite lattice upon film crystallization. 

Researchers at The University of Toledo (UToledo), Northwestern University and University of Washington have focused on the stability of perovskite solar cells, and reported an adjustment to the chemical structure of a key component of a tandem cell that allows it to continuously generate electricity for more than 1,000 hours.

Image from Joule

“State-of-the-art all-perovskite tandem cells with a conventional hole-transfer layer can only continuously operate for hundreds of hours,” said Dr. Zhaoning Song, a co-author and assistant professor in the Department of Physics and Astronomy at UToledo. “Our innovation prolongs the stability of these devices, advancing all-perovskite tandem technology and bringing it closer to practical application.”

Researchers from King Abdullah University of Science and Technology (KAUST) have reported four-terminal perovskite/perovskite/silicon triple-junction tandem solar cells, with the device structure comprising a perovskite single-junction top cell and monolithic perovskite/silicon tandem bottom cell.

The cells reportedly yielded a 31.5% power conversion efficiency, which the team said is the highest efficiency ever reported for perovskite-based 4-T and triple-junction tandem solar cells. The key feature of the cell is the hole transport layer of the top perovskite cell, which was engineered with self-assembled monolayers.

Sunmaxx PVT, a German developer and manufacturer of photovoltaic-thermal solar modules, and Oxford PV, a producer of high-efficiency tandem solar cells, announced the launch of the “Solar Hammer" module. This partnership marks the first use of perovskite-on-silicon tandem solar cells in a photovoltaic thermal module, enabling a very high conversion efficiency. Both the cells and the modules are produced in Germany.

Sunmaxx PVT’s modules combine proven thermal management technology from the automotive industry with photovoltaics, leading to a total conversion efficiency of 80%, certified by Fraunhofer ISE. Oxford PV’s perovskite-on-silicon tandem solar cells have broken multiple records for conversion efficiency. In combination, these technologies enable more usable electricity and heat to be generated from the sun’s energy. The new module comes at a record efficiency of 26.6% electrical and 53.4% thermal efficiency, totaling 80% overall efficiency on aperture area level of 1.63 m². The electrical power of the module with 6×10 M6 cells is 433 W, surpassing the previous record of Fraunhofer ISE.

LONGi Green Energy Technology has announced a new world record efficiency of 30.1% for a commercial M6 size wafer-level silicon-perovskite tandem solar cell at the 2024 Intersolar Europe event in Germany. This new record comes less than a week after LONGi announced a new world record of 34.6% tandem solar cell efficiency at the 2024 SNEC EXPO in Shanghai, and it also breaks the previous world record of 28.6% wafer-level tandem solar cell efficiency on M4 commercial size wafers in May 2023.

The commercial M6 size wafer-level silicon-perovskite tandem solar cell was independently certified by the Fraunhofer Institute for Solar Energy (Fraunhofer ISE) in Germany.

Oxford PV has announced a record-setting 26.9% efficiency for its double-glass, 60-cell “residential sized” perovskite tandem module at the Intersolar Europe 2024 event. The module reportedly has a surface area of a little over 1.6 m square meters (1m x 1.7m) and weighs a little under 25 kg, “the ideal size for residential applications,” according to Oxford PV.

Oxford PV produces the proprietary high efficiency tandem solar cells at its manufacturing facility in Brandenburg an der Havel, Germany, and uses both in-house and contract services for the module assembly.

Researchers in China, led by Nanjing University, have designed a tandem perovskite-silicon solar cell with a top perovskite device based on an absorber treated with n-butanol (nBA), which reportedly reduces the detrimental effects of moisture in manufacturing processes carried out in air environment. The resulting PV device is said to have improved charge collection.

The nBA used by the team is a clear, colorless alcohol used as a cleaning agent in many industries, including electronics manufacturing. The team explained that it offers low polarity and saturation vapor pressure and ensures that the typical detrimental effects of moisture in perovskite cell fabrication in an ambient environment can be significantly reduced.

Swift Solar has announced the close of its $27 million Series A financing round. The round was co-led by Eni Next and Fontinalis Partners. Also joining the round are new and existing investors including Stanford University, Good Growth Capital, BlueScopeX, HL Ventures, Toba Capital, Sid Sijbrandij, James Fickel, Adam Winkel, Fred Ehrsam, Jonathan Lin, and Climate Capital.

In total, Swift Solar has raised $44 million for its mission to transform the solar energy landscape with perovskite tandem solar products. Proceeds from this round will accelerate Swift Solar’s scaling of efficient and stable tandem technology as the Company prepares to break ground on its first factory. Swift Solar also plans to build a factory in the U.S. in the next two to three years to manufacture thin-film solar.

Researchers from the Ningbo Institute of Materials Technology and Engineering at the Chinese Academy of Sciences recently reported a novel perovskite/silicon tandem solar cell based on flexible ultrathin silicon, with a thickness of about 30 µm.

Despite major progress in the efficiency of rigid perovskite/silicon tandem solar cells, flexible perovskite/silicon tandem solar cells have remained elusive. The team explains that this is due to the challenge of enhancing light absorption in ultrathin silicon bottom cells while maintaining their mechanical flexibility.