The TaiyangNews Cell & Module Production Equipment & Processing Materials Conference, held virtually on September 2, 2025, explored the latest innovations in production equipment and consumables across the solar cell and module value chain.
Moderated by TaiyangNews Head of Technology Shravan Chunduri, the panel focused on key trends shaping the PV cell and module manufacturing industry. Panelists included Jerry Liao (CTO, Leadmicro), Fangqing Guo (Director of New Technology Development, DKEM), and Sukumar Madugula (Sales Director, RCT Solutions).
This transcript is an edited and summarized version (for clarity) based on the full discussion available in the accompanying video, which can be found on the TaiyangNews YouTube Channel.
TaiyangNews: Looking at the trends in Markus Fischer’s ITRPV presentation, did anything surprise you, or was it all as expected?
Sukumar Madugula (RCT Solutions): The ITRPV is the industry roadmap everyone follows, but things are moving faster than predicted. Many expectations changed between 2023 and 2024, even from the top 4 firms. In India, especially outside China, the situation is very different. While TOPCon technology is now the base standard and technically sound, it still has challenges in large-scale deployment. In India, we lack the skilled workforce and resources to implement it quickly and achieve the same high efficiencies shown elsewhere, such as 25.5%. We don’t see such a stable line at a GW-scale yet, so hopefully this should come next year.
Jerry Liao (Leadmicro): I see technology advancing much faster than before, as the ITRPV data shows. The learning rate in recent years has been very steep, thanks to the global PV community. This bodes well for the industry’s future. We may see 500–650 GW of global installations this year, which sets strong expectations for the future.
Fangqing Guo (DKEM): I think ITRPV has made a very accurate prediction. Predicting next year’s developments is always difficult, especially regarding layouts and customer costs. Our customers tend to move more aggressively than we expect. For example, just a year ago, I could never have imagined that screen openings would drop below seven microns.
It’s hard to predict, but that’s exactly why we need to prepare—even more aggressively than our customers—so we can meet their requirements.
TaiyangNews: TOPCon is currently the leading cell technology. But Jerry, you said in your presentation that TOPCon is ‘past tense’. Is that really the case?
Jerry Liao (Leadmirco): Technically, TOPCon is already very mature. In China alone, more than 800 GW of TOPCon capacity has already been deployed – far more than the global demand of 500–600 GW mentioned in the ITRPV report. This overcapacity means new TOPCon expansions in China will likely be limited.
Outside China, though, it’s different. ITRPV still sees TOPCon as the mainstream technology for the next 10 years, which matches the typical equipment lifetime. This makes it a good choice for new deployments outside China.
That said, there’s still room for improvement. Hot areas of development include polyfinger contacts and edge passivation, which only entered mass production this year and are being scaled rapidly. Technologies like zero-busbar or moving to copper also offer cost-reduction potential.
However, each improvement adds steps to the process, making TOPCon increasingly complex – eventually reaching a level of complexity similar to TBC.
TaiyangNews: How is industry adoption of polyfingers? And another topic – bifacial poly. You discussed this in one of our previous conferences, but now it’s hardly mentioned. Are we skipping bifacial poly and going directly to BC? And coming back to my first question, how is the adoption of polyfingers progressing?
Jerry Liao (Leadmicro): To be honest, we spoke about polyfingers and edge passivation last year. But edge passivation has advanced much faster – it’s already in mass production since June-July this year. Polyfingers, however, remain in small-scale production evaluation.
Everyone knows the direction: making the rear-side poly thinner to remove it. But technical hurdles in mass production, especially yield and laser-source stability, are slowing progress. High-power laser sources are required, and those challenges mean adoption is still relatively slow.
TaiyangNews: Edge passivation and rear polyfingers aren’t really comparable. You’ve shown a throughput of 40,000 wafers per hour for edge passivation with simple equipment that you can put in a corner. But polyfinger technology is really the next-generation step within TOPCon, right?
Jerry Liao (Leadmicro): Yes, definitely. Polyfingers will be deployed sooner or later – we’ve invested heavily in resolving the issues. But we have to understand that mass production is different from a pilot line: in pilots, you prove efficiency gains; in mass production, you must prove stability. Nevertheless, we believe deployment will happen very soon.
TaiyangNews: In one sentence, what’s your take on bifacial poly? Some argue there’s little benefit to front-side poly due to LECO, yet it’s still on some roadmaps.
Jerry Liao (Leadmicro): We’re exploring all directions. Bifacial poly’s process complexity is already similar to back-contact (BC) technology. BC gains from very high front-side efficiency but loses bifaciality; bifacial poly gains bifaciality but loses some front-side efficiency. Each has its pros and cons.
TaiyangNews: Sukumar, your presentation focused on modules, but you’ve also worked extensively with cell lines. How do you see the state of cell manufacturing technology across the markets where you’re active – from India to the US? And how ready is the technology for deployment?
Sukumar Madugula (RCT Solutions): In India, large-scale TOPCon projects began last year, with several GW-scale plants already announced or under construction. We’re actively engaged in major engineering projects and site preparations to bring this capacity online. India could add 15-20 GW of new cell lines within the next year, potentially reaching 30-35 GW by the end of next year. The domestic content requirement (DCR) market is also expected to be around 30-40 GW, which could lead to overcapacity by 2028-29.
We aim to stand out by focusing on cost per watt, which remains the key metric. TOPCon is attractive today, given its lower capital costs and cheaper implementation, supported by many suppliers.
In Europe, module manufacturing is growing, and cell capacity is slowly expanding through partnerships between Asian and European players. However, in the US, policy and market uncertainties are limiting growth for now. We’re watching the situation closely over the next few quarters.
Globally, after Asia, the US is still the biggest market. We expect more cell line activity there next year, especially in PERC, while TOPCon patent issues are resolved or as companies shift to back-contact (BC) concepts via joint ventures. Co-investment and partnerships are already emerging, and I anticipate a rise in cell manufacturing activity mid-next year as India’s expansion stabilizes.
TaiyangNews: Leadmicro is not just a Chinese equipment supplier, but it has a global footprint. From your perspective, how is TOPCon cell manufacturing developing outside China? How do you see the lines, equipment, processes, and quality aspects playing out in other markets?
Jerry Liao (Leadmicro): Outside China, local regulations and environmental conditions are important factors. In terms of line design, we already have very capable suppliers, so that’s not a major challenge. Equipment is also less of an issue — with more than 800 GW of TOPCon deployed in China, there’s a large pool of proven equipment to choose from. The main challenge lies in process quality, which depends on skilled workers and localized supply chains, both of which will take more time to develop outside China.
TaiyangNews: How do paste suppliers view the evolution of TOPCon technologies, such as rear poly and bifacial poly, and their potential?
Fangqing Guo (DKEM): We see significant scope to improve TOPCon efficiency, whether through polyfinger or bifacial poly approaches. However, these bring technical challenges. For example, bifacial poly has issues with front-side absorption and controlling the so-called “J0,m” metal on textured surfaces. On planar surfaces, metal control is easier, but on textured pyramids, the paste can etch the passivation layer at the tips, making it hard to reduce metal residues despite recipe adjustments.
Compared to back-contact (BC) cells, bifacial poly struggles to match VOC levels, though its contact properties may be slightly better. That said, BC contact quality has improved a lot, with poly contact resistivity now below 2 Ω – very low compared to TOPCon’s front side. However, the metal residues on bifacial poly remain higher than with BC.
In our view, bifacial poly may still deliver some efficiency gains over standard TOPCon, but competing with BC is difficult. Polyfinger is already in mass production at some customers, but the efficiency gain is small – less than 0.1% – and may not justify the extra equipment cost. Still, we expect further optimization of paste, equipment, and processes to unlock more efficiency improvements, which is essential for the future of mass-production TOPCon.
TaiyangNews: Are there any silver-saving approaches for TOPCon? At a broader level, is your focus more on improving efficiency or reducing costs?
Fangqing Guo (DKEM): We’re working on both fronts. For the front-side paste, customers mainly focus on improving efficiency, so our goal is to enhance the performance of the front-side silver paste. On the rear side, the priority is cost reduction.
We take a step-by-step approach. First, narrowing finger line openings is a straightforward way to cut costs. We’re also working with customers on base-metal integration. For example, we’ve started introducing nickel into the paste as a cheaper alternative, though its content must stay below 20% to avoid significant efficiency losses.
For deeper cost cuts, we’re moving toward silver-coated copper paste – sometimes called high-copper paste – and eventually pure copper paste. Pure copper is still challenging because it requires new equipment and long-term reliability testing. However, silver-coated copper paste is already in mass production with several customers. It offers clear cost savings, maintains efficiency and reliability, and can be used with existing equipment with only minor additions like extra printers or curing machines. This makes it a more mature and practical solution today.
TaiyangNews: BC technology is drawing major attention, going by the ITRPV presentation, your own talk, and the solar shows full of BC modules. But the process is still complex, critical, and expensive, and we also face overcapacity. What’s the real incentive to move to BC now?
Jerry Liao (Leadmicro): BC holds the world record for single-junction crystalline silicon solar cell efficiency and is clearly the next step for high-efficiency technology, especially for higher-power modules. Customers focus on module output, so this matters.
We’re working to make BC production less challenging, just as we did with TOPCon at the start. As shown in my presentation, our improvements this year can cut equipment investment costs by around 40%. This dramatic reduction should encourage more, including new, investors to enter the next generation of solar cell technology.
TaiyangNews: On a scale of 1 to 10, with TOPCon equipment at 10, how robust is the current BC equipment supply?
Jerry Liao (Leadmicro): Honestly, BC and TOPCon equipment are very similar; mainly, the process differs, and BC generally needs more equipment. That’s why we’re working to push equipment technology further.
From what I presented, BC mass-production technology is already quite mature, especially with the 2-step LPCVD or 2-step poly process. The older 1-step method caused issues with boron and phosphorus diffusion, but they can be solved by separating the steps.
The main challenge now is reducing costs and improving yields. Every additional step tends to yield lower. When we first started with PE-TOPCon, yields were below 30%, but we raised them to over 97% within 6 months. Advancing cell and equipment technology always requires continuous effort to push boundaries.
TaiyangNews: Fangqing, how critical are pastes for BC cells, and how do they differ from those used in TOPCon?
Fangqing Guo (DKEM): Pastes are very important for BC cells, especially for p-poly. For example, our customers run paste experiments almost every day, while they do far fewer tests on processes like poly deposition or passivation. This is because paste performance, particularly in p-poly, still has significant potential to improve efficiency.
There’s strong competition in this area. Our competitors are constantly improving their pastes, and so are we. For n-type poly, the paste is quite similar to the rear-side paste used in TOPCon. But for p-type poly, it’s very different, as it contacts p-poly directly but must avoid leakage.
This is essentially a completely new, glass-free system compared to TOPCon’s front side. We believe there’s still a lot we don’t know yet, and potentially new paste systems to discover that could help our customers boost efficiency even further.
TaiyangNews: LECO was a real game-changer for TOPCon. Can it also be used for BC cells? If not, why?
Fangqing Guo (DKEM): Some of our customers have tried LECO on BC, but it’s quite different from TOPCon. In TOPCon, LECO works by removing aluminum from the front-side paste, which significantly reduces the overall metal content. But in BC cells, we don’t use aluminum in the paste, so the metal content is already very low.
Because of that, there’s much less room to reduce metal further. The only real area left to improve would be contact optimization, but the contact resistivity in BC is already very low. As a result, LECO brings little or no efficiency gain, so most customers are not interested.
There’s also a technical challenge: TOPCon’s structure separates the front and rear sides, making voltage application easier. BC puts everything on the same side, which makes LECO much harder to apply effectively.
TaiyangNews: Sukumar, looking at your global projects, what’s the key to success when ordering a module production line today?
Sukumar Madugula (RCT Solutions): Success today depends less on the equipment supplier and more on how well the company itself is prepared. This includes capital, site readiness, engineering, and skilled people.
Each region has its own challenges. In India, site approvals and market conditions are the main hurdles. In Europe, the biggest challenge is securing financing, because the market is open with no tariffs or duties – if companies manage to secure funding, they can succeed using competitively priced cells. In the US, compliance requirements are the most challenging issue.
If I had to break it into 3 priorities:
Capital – especially outside Asia.
Site preparation and engineering.
Skilled workforce – to launch quickly and maintain high quality.
Having the right people and skill sets is critical to achieving consistent quality and meeting vendor standards.
TaiyangNews: One last question. Please share 3 key technical recommendations for investors planning to build a cell factory outside China, so they can compete with local peers and Chinese market leaders when exporting to open markets.
Sukumar Madugula (RCT Solutions): Success depends on managing both CapEx and OpEx – not just focusing on the lowest equipment price but also on overall production cost and LCOE. Investors should carefully choose the right mix of equipment and operating conditions tailored to local realities like land and building costs. In regions outside China, especially Europe, scale matters – you can’t easily do GW-scale there, so integration and supply-chain ecosystems become critical. Examples like Turkey show it’s possible to build competitive cell lines if you have affordable electricity, a supportive government, and a strong local ecosystem.
Jerry Liao (Leadmirco): Sukumar covered most of it, but I’ll add: first, use local resources to create a competitive edge. Second, focus strongly on quality control. Overcapacity and price pressure have caused a noticeable drop in module quality in recent years, even though these products must last 25–30 years. Quality can become a differentiator. Finally, build a highly competent team. Manufacturing success depends as much on skilled operations as on technology.
TaiyangNews: Fangqing, can you bring the material supplier perspective into this equation?
Fangqing Guo (DKEM): Local policy and supply chains are critical. Even if suppliers want to serve a market, unfriendly local policies can make it difficult. A supportive policy environment and easy access to local resources help cell makers succeed and secure reliable materials and services.
TaiyangNews: So local sourcing is key. On that note, thank you all.
Individual presentations from the 4 speakers, as shared during the conference, and a conference summary can be accessed here.