TOPCon to remain the mainstream PV technology over the next several years, despite parallel development of BC, HJT, and tandem architectures
The company presented TNC 3.0 as the next step after TNC 2.0, combining multi-cut cells, overlapping layout, and improved passivation
Tongwei’s roadmap targets up to 670 W for modules based on the G12R format and about 760 W for larger G12 modules by 2027
The PV industry has undergone a rapid technology transition over the past few years. PERC technology has been steadily phased out as manufacturers pursue higher efficiency architectures. N-type technologies have consequently moved into the mainstream, with tunnel oxide passivated contact (TOPCon) emerging as the dominant technology in current module production.
During the TaiyangNews High-Efficiency Solar Technologies Conference 2025, Aran Huang, Overseas Technical Support Manager at Tongwei, presented the company’s perspective on the next phase of TOPCon development. The presentation, titled What’s the Next Level – TNC 3.0, introduced the company’s module platform, designed to increase module power while improving operational performance under real-world conditions.
Tongwei expects TOPCon to remain the dominant technology for the next 3 to 4 years. Technologies such as BC, heterojunction (HJT), and tandem cells are also advancing. However, TOPCon still offers a strong balance of reliability, efficiency potential, and manufacturing scalability, said Huang.
To explain the evolution of products, she first described Tongwei’s TNC 2.0 platform. According to the company, module performance can be improved through 2 main approaches. The first is optimization at the cell level, such as improving light trapping, applying anti-reflection coatings, narrowing finger widths, and reducing current leakage. The second method involves module-level design improvements, including AR-coated glass, narrower ribbons, and reflective materials placed between cell gaps.
Tongwei says it introduced several new features in TNC 2.0 based on these principles. These include TPE edge protection technology, which adds a protective layer at the cutting edge of smaller cells. This design helps recover part of the cutting damage and can improve cell efficiency by more than 0.2%. Another improvement is stencil printing, which enhances the collection of current and reduces shading losses. Tongwei also introduced Poly Tech, designed to increase bifaciality from roughly 80% in conventional TOPCon modules to about 88%.
With these improvements, TNC 2.0 modules reached power levels of 715 W for G12-66 double-glass modules, 615 W for G12R-66 modules, and about 475 W for G12R-48 modules, adds Huang.
The presentation then moved to the TNC 3.0 platform, which focuses mainly on changes in cell segmentation and module layout. Traditional half-cut modules divide each cell into 2 pieces. Tongwei’s new approach divides each cell into 4 smaller pieces. This multi-cut design reduces the current flowing through each segment, which lowers resistive power loss.
Additional cutting normally increases the risk of cutting damage. However, Huang said the company’s TPE protection technology helps repair cutting defects and reduces cutting loss by more than 16%. These smaller cell segments enable the module to achieve significantly lower internal power loss compared with conventional full-cell designs.
Another key change is in the module’s optical layout. In conventional half-cut modules, ribbons between cells create inactive areas where sunlight cannot be captured. Tongwei’s TNC 3.0 modules partially overlap the smaller cell segments. This overlapping structure reduces inactive space between cells and improves light capture.
Tongwei estimates that these combined electrical and optical improvements enable TNC 3.0 modules to reach an output of about 670 W. Huang described this as roughly 40 W higher than traditional TOPCon modules and around 20 W higher than TNC 2.0 products.
The company also reported improvements in operational performance. Enhanced passivation increases open-circuit voltage and improves the module temperature coefficient. Under high operating temperatures, the power advantage of TNC 3.0 modules could reach up to 45 W compared with conventional designs, says Huang. The design also achieves bifaciality levels of about 85%, enabling higher rear-side energy yield in utility-scale and commercial & industrial installations.
Another feature Huang emphasized was anti-shading performance. In a half-cut module, shading affects a larger portion of each cell. In TNC 3.0, because each cell is divided into 4 smaller sections, shading on one part affects only 1/4th of that cell’s area. This improves shade tolerance and reduces the associated power loss, said Huang, adding that this anti-shading capability has been certified by TÜV laboratories.
She shared Tongwei’s roadmap for further development of TNC 3.0. For the G12R-66 format, Tongwei targets around 655 W in 2026 and 670 W in 2027. For the larger G12-66 modules, the company expects around 750 W in 2026 and 760 W in 2027. In rooftop applications, Tongwei’s G12R-48 module is expected to reach around 480 W in 2026 and 500 W in 2027. She added that black-frame and full-black versions would typically deliver about 5 W lower output than the standard version.
Tongwei also indicated that TNC 3.0 will not be limited to standard module designs. Huang said the company is developing scenario-specific solutions for desert installations, offshore projects, and anti-dust environments. For offshore systems, Tongwei adds extra protective measures to maintain module stability. For dust-prone applications, the company is modifying the frame design to improve dust-related performance.
To access Tongwei Solar’s presentation, click here.
