The SNEC 2025 recently concluded in Shanghai, drawing global attention as the year's premier expo in the solar industry. During the event, Dr. Dengyuan Song, CTO of DAS Solar, delivered a keynote titled "Key Technologies and Future Research Directions for DAS Solar's TOPCon 5.0 High-Efficiency Cells" at the forum on TOPCon, HJT, and BC technologies. Meanwhile, at the International Conference on Photovoltaic Polymers, Mr. Jianfang Dai, Deputy General Manager of DAS Solar's Central Research Institute, presented a speech on "Progress in N-type High-Efficiency Modules: 0BB Technology and Current Optimization Solutions".
Dr. Dengyuan Song, CTO of DAS Solar
As the global energy landscape continues its rapid shift toward decarbonization, technology iteration has become the key driver of industry growth. According to the China Photovoltaic Industry Association's Roadmap 2024-2025, TOPCon cell technology holds a 71.1% market share in 2024, solidifying its position as the industry's mainstream solution. With the transition from P-type to N-type cells being the fastest in PV history, projections indicate that TOPCon will rise to 81.4% in 2025 and stabilize at 60% by 2030, highlighting its long-term potential.
Since its founding, DAS Solar has committed to TOPCon as its core technology, achieving full-spectrum breakthroughs from process to product. Through continuous innovation and strategic foresight, the company has completed five generations of TOPCon evolution. According to Dr. Song, the latest generation, TOPCon 5.0, represents a leap in five dimensions—structure, mechanism, process, materials, and principles. With a mass production efficiency of 27% and open-circuit voltage reaching 746mV, it combines high efficiency with cost-effectiveness, reinforcing DAS Solar's role at the forefront of solar innovation.
The TOPCon 5.0 cell incorporates PolyFinger architecture on the rear side, utilizing laser patterning to form micron-scale light-trapping structures that boost infrared absorption by 0.3%-0.5%. Nanocontact metallization, driven by nanosecond laser-induced processing, lowers contact resistance to below 0.5 mΩ·cm², enabling faster, more efficient electron flow and raising open-circuit voltage. A new high-aspect-ratio trapezoidal grid line design, enhanced by advanced paste and screen printing techniques, increases grid surface area and reduces resistance, pushing the fill factor above 85%. Edge recombination losses are addressed with hybrid passivation materials that combine organic and inorganic components, improving edge efficiency. Finally, an innovative stacked-film emitter passivation structure mitigates UVID degradation, achieving less than 0.8% loss under UVID120 testing, and ensuring long-term reliability and sustained high performance. Together, these core innovations unlock greater life-cycle power generation and set new standards in cell durability and efficiency.
Dr. Song also emphasized that technologies such as TOPCon, HJT, and TBC are not mutually exclusive but complementary in shaping a diversified technical ecosystem. Guided by its "One Core, Three Branches" strategy, DAS Solar has built a comprehensive innovation framework centered on TOPCon while simultaneously advancing DBC, TSiP (perovskite/silicon tandem), and SFOS (silicon-based multiphoton conversion) technologies. The company's TSiP tandem cells using TOPCon 5.0 as the bottom cell have achieved 33.5% efficiency in two-terminal configurations. At SNEC, DAS Solar and UtmoLight jointly launched a 26.8%-efficient, 2.82 m² four-terminal TSiP 2.0 tandem module, establishing a new benchmark for next-gen tandem technologies. In parallel, the company is collaborating with the University of New South Wales to develop SFOS technology, aiming for 40% efficiency in the long term.
Mr. Jianfang Dai, Deputy General Manager of DAS Solar's Central Research Institute
At the International Conference on Photovoltaic Polymers, Dai highlighted DAS Solar's advances in 0BB (zero busbar) interconnection, identifying it as a transformative approach for boosting module performance and reducing manufacturing costs. 0BB technology eliminates front-side busbars, reducing silver paste consumption and shading while enhancing energy conversion efficiency. Dai noted that while 0BB offers significant advantages for TOPCon, HJT, and BC cells, it also faces challenges under high-temperature soldering, thermal cycling, and long-term outdoor exposure. DAS Solar has addressed these barriers with proprietary processes and materials, achieving a 10% reduction in silver usage while raising module efficiency above 24%. The solution has passed triple IEC reliability standards, positioning DAS Solar's 0BB platform as a balanced model of economics and durability for the industry.
Driven by a firm commitment to innovation, DAS Solar has fully deployed a high-performance R&D matrix across TOPCon, DBC (Diamond series back-contact), TSiP, and SFOS, delivering increasingly efficient and reliable solutions through continuous iteration. With a forward-looking approach and a strong foundation in next-generation PV technology, DAS Solar is poised to make lasting contributions to the global energy transition and sustainable development.