LONGi Sets 35.5% Tandem Solar Cell Record as Global Efficiency Advances Accelerate

Chinese firm LONGi announced a certified conversion efficiency of 35.5 % for its crystalline silicon‑perovskite tandem solar cell, a new world record confirmed by the European Solar Test Installation (ESTI). The achievement follows a rapid series of improvements—33.9 % in November 2023, 34.6 % in June 2024, 34.85 % in April 2025, and 35.2 % earlier this year—demonstrating the company’s tiered R&D pipeline that moves one generation into mass production while another is under development.

LONGi also reported near‑industrial‑scale efficiencies of 34.3 % on a 261 cm² cell and 32.2 % on a 274 cm² cell, and tandem modules reached 31.4 % and 29.4 % conversion, both independently certified. These results place silicon‑perovskite tandem technology close to its theoretical limit of about 43 % and signal a major step toward large‑scale deployment.

Other research teams reported parallel progress. An international collaboration led by Monash University demonstrated a commercially sized indium‑free tandem cell using tin‑oxide, attaining 31 % efficiency while cutting material costs by 99 %. Scientists at Helmholtz‑Zentrum Berlin and partner universities introduced a new molecule (MeXT) that raised perovskite cell efficiency to 26.19 % and improved durability. A German‑Lithuanian team unveiled a carborane‑based electron‑transport material that enhances perovskite‑silicon tandem performance and stability. South Korea’s Qcells secured TÜV Rheinland certification for its 28.6 % perovskite‑silicon tandem devices, confirming compliance with IEC and UL reliability standards.

Collectively, these developments underline accelerating advances in tandem photovoltaic technologies, promising higher power output, lower material costs, and faster commercial rollout in the global clean‑energy transition.