Chinese PV manufacturer LONGi has secured independent certification from the European Solar Test Installation (ESTI) for its crystalline silicon-perovskite tandem solar cell reaching a record power conversion efficiency of 35.5%, unveiled at the 2026 Solar and Energy Storage Innovation Conference.
Silicon-perovskite tandem architecture is widely recognized as a leading pathway for next-generation high-efficiency photovoltaics. By stacking a perovskite top cell onto a crystalline silicon bottom cell, the design delivers a far higher theoretical efficiency ceiling than conventional single-junction silicon cells.
This 35.5% milestone caps a multi-year series of steady efficiency upgrades from LONGi’s tandem R&D team. The firm’s tandem cell performance has climbed sequentially from 33.9% (November 2023), 34.6% (June 2024), 34.85%, 35.2%, and now 35.5%.
LONGi also validated large-area scalability of the technology, posting certified efficiencies of 34.3% on a 261cm² tandem cell and 32.2% on a 274cm² device. For finished tandem PV modules, the company achieved independently verified conversion rates of 31.4% and 29.4%, both documented in the latest Solar Cell Efficiency Tables.
In May 2026, LONGi’s 35.2% two-terminal silicon-perovskite tandem cell was formally included in the 68th edition of the Solar Cell Efficiency Tables, compiled by Professor Martin Green’s team at the University of New South Wales.
Alongside tandem cell progress, LONGi announced a new efficiency record for its hybrid interdigitated back contact (HIBC) silicon cell, hitting 28.13% efficiency, certified by Germany’s Institute for Solar Energy Research Hamelin (ISFH). This surpasses the brand’s prior January 2026 HIBC benchmark of 28.04%.
Modules built with the updated HIBC cells reached a certified 26.4% conversion efficiency, verified by the U.S. National Laboratory of the Rockies (NLR), up from LONGi’s previous 26% module record.
The company also showcased its latest mass-production product at Intersolar Europe 2026 last month: the Hi-MO 9 Prime module series, rated at 680W output with a module conversion efficiency of 25.2%.
