DAS Solar, a leading N-type technology PV manufacturer, achieved the open-circuit voltage 735mV for 'large-sized' cell measuring 333.8 cm² cell by DAS Solar's independently TOPCon 4.0 technology: A world record for TOPCon cell open-circuit voltage. The record was certified by the National PV Industry Measurement and Testing Center (NPVM).

Certification report of TOPCon cells I-V characteristics

DAS Solar is dedicated to continuous exploration and rigorous research in N-type technology, consistently surpassing industry standards in cell and module efficiency. With the progression from TOPCon 1.0 to 4.0, this achievement represents a breakthrough in innovative cell passivation structure technology. The open-circuit voltage has steadily increased from 701mV to 735mV.

The open-circuit voltage progresses from DAS TOPCon 1.0 to 4.0

Dr. Song Dengyuan, CTO of DAS Solar and Chairman of the SEMI Standards PV and PV Materials China Joint TC Chapter, said "Open-circuit voltage is the most important technical index of solar cell, symbolizing the potential improvement in solar cell efficiency. Over the past year, the open-circuit voltage has increased by more than 15 mV. This growth is significantly surpassing the speed of open-circuit voltage improvement in other types of cells, indicating the substantial efficiency enhancement potential of TOPCon cells. TopCon 4.0 technology combines innovative features, including a new charge carrier transport mechanism, a novel cell structure design, metallization techniques, and new materials. Additionally, laser-induced high-throughput charge carrier metallization has a significant impact on enhancing cell efficiency, showcasing DAS Solar's capability in leading integrated innovation.

The open-circuit voltage of the world's Top 3 TOPCon cells

According to Professor Martin Green's latest Solar Cell Efficiency Tables (Version 63), Fraunhofer ISE reports the highest open-circuit voltage for TOPCon cells. There is a 724.1mV open-circuit voltage for small-sized (4cm²) TOPCon cells with a bifacial electrode structure, and 732.3mV for TOPCon cells with a P/N junction and TOPCon structure. DAS Solar TOPCon 4.0 cell with bifacial electrodes achieves an impressive open-circuit voltage of 735 mV. This represents a significant breakthrough in novel passivation technologies, signaling a crucial milestone for continuous efficiency improvement in the TOPCon cell technology.

Through process innovations, mass production cell technologies typically increase efficiency by 0.2-0.3% per year. By 2023, TOPCon cells have achieved nearly 1% of efficiency improvement, surpassing expectations in both speed and potential enhancement. Based on calculations from solar cell simulation modeling, utilizing the physical parameters of current efficiency improvement methods, TOPCon cells exhibit an efficiency potential surpassing 28%. DAS Solar will continue to explore and innovate in the future, consistently advancing the industrialization of TOPCon 4.0, TBC, SCPC, TsiX, and SOFS.