In the recent paper titled “Silicon heterojunction back contact solar cells by laser patterning”, LONGi Green Energy Technology Co., Ltd. (referred to as “LONGi”) reported for the first time that crystalline silicon solar cells have broken the 27% efficiency barrier, marking a significant advancement in photovoltaic (PV) technology. This milestone not only highlights the potential of back-contact (BC) solar cells for high efficiency and cost-effectiveness but also sets a new benchmark for the industry.
LONGi’s Central R&D Institute has driven this innovation through intensive research in silicon wafers and passivation technology, developing a dense heterojunction passivation contact and surpassing previous thermal constraints in heterojunction preparation. The developed process, involving a fully laser-patterned structure and a low-indium, silver-free metallization approach, enhances both efficiency and economic viability for future BC solar cell production.
This breakthrough comes after LONGi’s record-breaking announcement in May, where the independently developed HBC (heterojunction back-contact) solar cells achieved an efficiency of 27.30%, setting a new world record for monocrystalline silicon cells. This follows the previous record of 27.09% in December 2023, solidifying LONGi’s leadership in high-efficiency solar technologies.
Historically, crystalline silicon solar cells have seen three major technological advances: Al-BSF cells (below 20% efficiency), PERC cells (up to 25% efficiency), and TOPCon (breaking 25%). Looking forward, BC technology is positioned to lead the next wave of mass production, with efficiencies exceeding 26%. LONGi’s research points to this future, combining heterojunction technology with a BC structure to push efficiency beyond 27%.
LONGi’s long-term commitment to innovation is reflected in this being the third Nature publication by the Central R&D Institute since 2024, following earlier reports on world records in flexible silicon heterojunction and perovskite/crystalline silicon tandem cell efficiency. These achievements underscore LONGi’s leadership in solar PV technology innovation.
As a global leader, LONGi remains dedicated to advancing solar energy, driving technological breakthroughs, and promoting a more efficient and sustainable photovoltaic future through continued innovation and industry collaboration.
