LONGi Sets Dual World Records in Solar Cell Efficiency for HIBC and Tandem Technologies

LONGi, a global leader in solar technology, has announced two new world records in photovoltaic conversion efficiency, showcasing major advancements in both back contact and tandem solar cell designs.

27.81% efficiency in heterojunction interdigitated back contact (HIBC) solar cells

LONGi has achieved a world-record efficiency of 27.81% for its n-type silicon Heterojunction Interdigitated Back-Contact (HIBC) solar cell. This result was independently certified by the Institute for Solar Energy Research in Hamelin (ISFH), Germany, under standard test conditions.

The HIBC cell combines heterojunction technology with a back-contact architecture, eliminating front-side metallization to maximize light absorption. Built on industrial-grade gallium-doped silicon wafers, the device exhibits excellent passivation quality, high open-circuit voltage, and optimized carrier collection. This achievement marks the highest recorded efficiency for a commercial size monofacial silicon solar cell.

34.85% efficiency in crystalline silicon-perovskite tandem solar cells

LONGi also set a new world record of 34.85% conversion efficiency for its crystalline silicon-perovskite tandem solar cell, certified by the U.S. National Renewable Energy Laboratory (NREL).

The cell employs a two-terminal structure, integrating a perovskite top sub-cell with a crystalline silicon bottom sub-cell. Developed at LONGi’s Xi’an R&D center, this tandem architecture takes advantage of complementary bandgaps to maximize solar spectrum utilization. The result approaches the theoretical efficiency limit of 43% and confirms LONGi's leadership in tandem cell research.

LONGi’s series of cell efficiency world records aim at the commercialization of new solar technologies

Since 2021, LONGi has set the photovoltaic (PV) cell conversion efficiency record 19 times. In 2021 alone, the company broke the record seven times, achieving 25.21% efficiency with TOPCon solar cells and 26.30% with heterojunction (HJT) solar cells. The streak continued in 2022 with another seven records, pushing HJT efficiency to 26.56%. In 2023, LONGi expanded its technology portfolio, reaching 27.09% efficiency with heterojunction back contact (HBC) solar cells and 33.9% with crystalline silicon-perovskite tandem cells. These milestones reinforced LONGi’s commitment to back contact technologies, a strategic direction the company has pursued since 2022. In 2024, LONGi secured two world records: 27.30% for crystalline silicon heterojunction back contact (HBC) solar cells and 34.6% for crystalline silicon-perovskite tandem solar cells. That same year, the company achieved a groundbreaking 30.1% efficiency with a commercial M6 wafer-sized silicon-perovskite tandem solar cell.  

Additionally, in 2024, LONGi launched its Hybrid Passivated Back Contact (HPBC) 2.0 technology and now holds the module efficiency world record of 25.4%, officially certified by the Fraunhofer Institute for Solar Energy Systems ISE.

These milestones align with LONGi’s strategic roadmap to industrialize next-generation solar technologies.

‍