Chinese cell manufacturer Maxwell has developed a perovskite/silicon heterojunction technology (HJT) tandem solar PV cell with a conversion efficiency of 32.5%.
Completed in February this year with a cell of G12H size—210mm by 105mm—the latest conversion figure is an improvement on a figure of 32.38% completed at the turn of the year. The latest milestone was validated by the Fraunhofer Institute for Solar Energy Systems in Germany.
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The newest cell was built on an industrial-grade 110μm-thick silicon wafer, according to Maxwell, and uses “perovskite passivation and innovative low-damage TCO materials and supporting processes”. While the company did not specify when the cell would be included in modules on sale, it noted that it designed the new cells with “industrial scalability” in mind.
However, the news follows Maxwell’s signing with a cell supply contract for perovskite/silicon HJT cells, with what it called a “Chinese new energy company” in December 2025, suggesting that the company’s perovskite/silicon HJT cells are in a relatively mature stage of development. Maxwell said of this collaboration that it would enable the client to build a mass-production line for G12H full-size tandem cells.
The news also comes as Maxwell makes a number of advancements in other solar cell technologies. Last month, the Institute for Solar Energy Research Hamelin, also in Germany, verified its 26.92% efficiency HJT cell, built to the same dimensions as the perovskite/silicon HJT cell, but without the same materials.

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