LONGi Solar says it has set a new world record for heterojunction (HJT) solar cell power conversion efficiency with 26.30%, and that it is the world's 'highest' efficiency for a front-back contact (FBC), meaning the cell has contacts on both sides and is not a back contact cell. This exceeds the company's claim of 25.82% claim for the same technology in less than a week's time (see 25.82% Efficiency For HJT Solar Cells).
Germany's Institut für Solarenergieforschung (ISFH) has validated the new record by the Chinese company.
LONGi shared, "From 25.26% through 25.82% to the latest 26.30%, LONGi has now achieved the rare feat of setting HJT cell efficiency world records three times in six months. Additionally, its N-type and P-Type TOPCon cells have also achieved the world's highest conversion efficiency of 25.21% and 25.19% respectively." However, the company missed the top seed position in TOPCon with 0.04% margin.
With more than 25% efficiency, the management opined, there is a valuable reference path for cost reduction in HJT industrialization.
To reach the claimed efficiency level, LONGi said its R&D department developed a new process to effectively lower the contact resistance of the interface, thereby improving the fill factor (FF) and increase the cell density that has now reached 40.49mA/cm² on an M6 9BB cell. It explained, "The fill factor (FF) of the certified cells breached the threshold of 86%, reaching 86.59% and achieving the world's highest level for silicon cells."
Sharing the changes it incorporated over the HJT cell for which it achieved 25.26% efficiency in June 2021, the company optimized the microcrystalline N window layer to further increase current density with a new intrinsic layer structure developed to enhance passivation performance and increase the Voc up to 2mV. It also applied a completely indium-free TCO process.
LONGi is one of the participants in TaiyangNews' Solar Module Innovations Conference—For Building & Utility-Scale Power Plant Applications scheduled to be held on November 15 & 16, 2021, virtually. Registrations to the event are free and can be done here.
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