Behind the Record-Breaking Achievements: How TOPCon Won This Peak Battle of Battery Technology

Introduction:
In this unprecedented cold winter, how can photovoltaic companies break through involution? Is it ample cash reserves? Is it cost control capabilities? Or is it simply a "coincidence" of overseas production capacity layout? In my opinion, these may only be icing on the cake. The ultimate competition is undoubtedly the ability to iterate technology. Therefore, there was this year's battle of battery technology, the noise of which even far surpassed the cruel supply and demand contradictions and overseas tariff disputes. The reason is simple: technological advancement undoubtedly accelerates the grand opening of a new era of new energy freedom and a more brilliant material life for humanity! At present, the photovoltaic industry, from the extreme pursuit of front-side efficiency to the extreme optimization of double-sided rate, then to the consideration of the optimal economic efficiency principle of vertical installation in some scenarios, and finally to the consideration of the correlation between cost and efficiency through model optimization by operators...These profound changes that have never been seen before in the photovoltaic industry are telling us: the world is vast, different scenarios and even different installation methods are all giving rise to a diversified trend in the demand for component technology. From the perspective of international game, only continuous technological leadership is the only effective way to break through trade barriers. Based on the above understanding, Photovoltaic Notes pays special attention to excellent companies that have achieved outstanding achievements in multiple areas of photovoltaic technology. Recently, Tongwei Co., Ltd. has achieved remarkable results: the efficiency of the TNC G12R-66 component has soared to an astonishing 25.28%! This has shocked the industry and greatly expanded the space and imagination of mass production efficiency of TOPCon technology. So, how did Tongwei open the door to the technological leap in component efficiency?

01

The Genes of Technology

Liu Hanyuan is a technology enthusiast: He comes from an engineering background, is passionate about technological innovation, and loves to apply technological innovation to the ultimate improvement of productivity. Not only in the aquaculture and feed industries, but also in the photovoltaic industry, Liu Hanyuan has personally participated, deeply grasped the context of technological development, and made powerful and forward-looking judgments on industry trends.

In 2022, Liu Hanyuan personally led the writing and publication of a book titled "The Vision of the Solar Energy Revolution in the Next Forty Years," systematically expounding his views on the photovoltaic industry, defining and describing the technological trends and green future of the human solar energy era.

After studying it from beginning to end, I still felt unsatisfied and read it again and again. The leader of a company worth hundreds of billions of dollars, describing the future in a calm and collected manner, is not a momentary whim, but a consistent love, which has led to a deep understanding of technology and industry and foresight for the future.

It can be seen that the persistence in technology and the deep insight into the industry are deeply ingrained in Tongwei's corporate culture and genes. Therefore, it has two unlimiteds: unlimited R&D investment and unlimited talent cultivation!

While industrializing a technology, Tongwei also leaves room for improvement for the next generation of technologies, making it one of the few companies that have truly achieved large-scale benign transformation of PERC batteries. In addition, in the face of the industry trend of the widespread adoption of N-type technology in 2025, Tongwei's technological research and development reserves are even more strategically forward-looking—it has reserved at least three technological iteration upgrade spaces for the TNC technology route, planning for a longer-term future.

Overview of the Major Progress of Tongwei TNC Technology:

• 2020

• Layout of TOPCon technology;

• 2021

• Construction of the industry's first 210 PECVD Poly battery pilot line;

• 2023

• The tubular PECVD technology led by Nantong University/Microguide and Tongwei was featured on the cover of the well-known photovoltaic science journal "Progress in Photovoltaics" (PIP) in January and March 2023. China's tubular PE-Tox&Poly achievements filled an industry gap, received widespread international recognition and reprints, and achieved innovative breakthroughs and leadership in TOPCon battery manufacturing technology;

• Tongwei's "High-Efficiency Silicon Passivated Contact Solar Cell (TNC) Technology" was successfully selected for the "2023 Photovoltaic Industry Innovation Achievements Recommendation Catalog" selected by the China Photovoltaic Industry Association, becoming the only TOPCon battery technology selected in the industry;

• 2024

• In April, the power of the TNC M10 standard-size component reached 613.2W;

• In May, the power of the TNC G12 standard-size component reached 743.2W, creating a double record for TOPCon components in the industry;

• In December, Tongwei Solar's independently developed "High-Efficiency N-type TOPCon Solar Cell" successfully won the "Sichuan Province Major Technological Equipment First-of-its-Kind Product" certification. This is the first time Tongwei Solar has received this honor, and it is also the first time a solar cell product has been selected since Sichuan Province launched the major technological equipment first-of-its-kind certification work in 2013, achieving a breakthrough for solar cells in the list of major technological equipment first-of-its-kind products in Sichuan Province;

• On December 24, under the standard size of 2384*1303mm, the front power of Tongwei TNC 2.0 component reached 763.4 watts (approximately 40 watts higher than the power of similar components in the market), and the conversion efficiency exceeded 24.58%; under the standard size of 2382*1134mm, the front power of Tongwei TNC 2.0 component reached 663.5 watts (approximately 40 watts higher than the power of similar components in the market), and the conversion efficiency exceeded 24.56%, setting new records for power and efficiency of two mainstream models of TOPCon;

• 2025

• On March 20, under the standard size of 2384*1303mm, the front power of Tongwei TNC 2.0 component reached 778.5 watts, and the conversion efficiency exceeded 25.06%; under the standard size of 2382*1134mm, the front power of Tongwei TNC 2.0 component reached 682.8 watts, and the conversion efficiency exceeded 25.28% (TÜV test), once again setting new records for power and efficiency of two mainstream models of TOPCon.

It is evident that technological innovation has been deeply engraved in Tongwei's genes, which will help Tongwei maintain its leading position in the industry in the future.

02

Leading the Transformation of Mainstream TOPCon Technology

Tongwei Co., Ltd.'s strong R&D capabilities in TOPCon technology were initially demonstrated in tubular PECVD technology. Unlike other TOPCon leaders who are deeply rooted in LPCVD, Tongwei chose the PECVD route and led the completion of its R&D and mass production introduction. According to InfoLink Consulting statistics, as a latecomer, the PECVD solution accounts for 56% of the market share and surpasses the pioneering LPCVD route.

As one of the few companies in the industry that has successfully and efficiently upgraded P-type cells to N-type TOPCon technology on a large scale, Tongwei continues to lead in the TOPCon 2.0 era, with module efficiency repeatedly breaking records... These achievements have been quite impressive to the industry.

On March 20, 2025, under the standard size of 2384*1303mm, Tongwei's TNC2.0 module achieved a front power of 778.5 watts and a conversion efficiency exceeding 25.06%; under the standard size of 2382*1134mm, Tongwei's TNC2.0 module achieved a front power of 682.8 watts and a conversion efficiency exceeding 25.28% (TÜV test), once again breaking the power and efficiency records for two mainstream versions of TOPCon. This result undoubtedly continues to consolidate the mainstream position and efficiency improvement potential of TOPCon technology, and further proves its technological leadership and forward-looking nature.

Although it is only an efficiency record for laboratory products, it is of great significance:

1. This time, the TOPCon module efficiency reached 25.28%, proving the huge potential for mass production efficiency improvement of TOPCon 2.0 technology, and significantly narrowing the gap with the front efficiency of BC technology.

2. This efficiency is all based on mass production technology, and Tongwei has already started preparations for mass production.

This not only brings a qualitative leap to Tongwei's TNC2.0 products, but also brings new hope and goals to TOPCon companies, pointing out the direction.

Tongwei's leading position in the TOPCon field has laid a solid foundation for its continuous 8 years as the world's leading cell shipper, and will continue to contribute to the progress of this current mainstream technology.

03

Tongwei's TOPCon 2.0 efficiency improvement

What technologies are behind it?

The technological sources behind the TNC2.0 module's efficiency innovation and industry-shaking achievements include: 908 technology (Tongwei's self-developed 0BB technology), Poly Tech, TPE technology (Tongwei's edge passivation technology), screen printing, etc., as well as the matching and optimization of module optical and electrical design, and the addition of high-throughput dense-packing technology for modules. The TNC-G12R 66 module efficiency record announced on March 20th has increased by 0.72% compared to the end of December 2024.

From the above-mentioned efficiency-enhancing technologies: from surface passivation to edge passivation, then to fine grid lines, and finally to the integration of technologies in the module field to improve overall performance, reduce efficiency loss from cells to modules, and greatly improve packaging technology. We see that this amazing achievement is not only a comprehensive upgrade and breakthrough in cell, module, and packaging technologies, but also a technology that can be directly introduced into large-scale mass production, providing strong support for comprehensively improving production efficiency in the future. Specifically:

1. Tubular PECVD poly deposition:

(Source: Professor Shen Wenzhong's keynote speech at a certain technology forum)

Professor Shen Wenzhong affirmed the advantages of P+Poly-Si using PECVD (superior to LPCVD), further improving the passivation effect of TOPCon cells and achieving efficiency improvement.

2. 908 main-gridless technology

Compared with the traditional 0BB technology, Tongwei's independently developed 908 technology reduces the main grid, reduces stiffness, and reduces stress, resulting in better overall power generation efficiency. The application of 908 technology reduces light shading and significantly improves efficiency.

3. TPE edge passivation technology and Poly Tech

TPE edge passivation also shows a significant improvement in efficiency, with an expected increase of more than 0.2% in module efficiency. The application of Poly Tech technology significantly improves the double-sided rate of TNC2.0 modules.

4. Others

Tongwei's screen printing technology, through disruptive full-opening screen design and process innovation, shows significant advantages in improving cell efficiency, reducing silver paste cost, and optimizing production stability; progress in the photovoltaic cell metallization field mainly involves copper paste, silver-coated copper, copper plating, and stacked grid technology; in the advanced packaging field, Tongwei's high-throughput dense-packing technology also continues to lead the industry in improving quality and efficiency.

Regarding the future efficiency improvement potential of the technology, Dr. Xing Guoqiang, Chief Technology Officer of Tongwei's photovoltaic business, said that the future efficiency improvement potential of TNC modules is still very large and far from over, and Tongwei has also reserved more efficiency improvement technologies that will be reflected in the future.

04

Why develop multiple technological routes?

Isn't redundancy a concern?

Public information shows that in June 2024, Tongwei's Global Innovation and R&D Center officially put into operation. This center is positioned to research various future breakthrough photovoltaic mainstream technologies, with complete advanced material testing centers and product reliability testing centers. Among them, the T6 workshop is the largest in the industry, with the highest pilot production capacity and the strongest upgrade capability.

In addition to continuously increasing investment in TOPCon technology, Tongwei has also accumulated fruitful R&D achievements in the HJT field, and has broken the power and efficiency records of HJT modules for 11 consecutive times. The company recently announced that its HJT modules have created a full-area efficiency record for crystalline silicon modules, further verifying Tongwei's continuous leadership and future-oriented capabilities.

In addition, the company also has leading R&D advantages in TBC and perovskite/crystalline silicon tandem technologies, which undoubtedly embodies Tongwei's R&D philosophy of using technology to prevent risks, find directions, position the market, and develop mainstream technologies for the company itself.

Dr. Xing Guoqiang, the helmsman of Tongwei's technology, is a typical technical expert who is rigorous, low-key, and pragmatic, and insists on starting from the first principles of technology to make comprehensive and objective evaluations. Dr. Xing believes that TOPCon is the current mainstream technology, while BC, HJT, and perovskite/crystalline silicon tandem technologies also have their own advantages. Before they are widely verified by the market, it is not suitable to conclude who is better. Tongwei's technological R&D philosophy is to "fully deploy mainstream technological routes in the industry," making full efforts in TOPCon, HJT, BC, and perovskite/crystalline silicon tandem technologies, and continuing to lead.

Tongwei's continuous research on various mainstream technological routes coincides with the current trend of diversified technologies and needs. The ultimate goal of technology is to provide customers with the best value products and combinations, rather than forcing a single technology on customers.

Unlike companies that solely bet on a single technological route, Tongwei's understanding, persistence, and choice of technology may be more timely and may create more value.