Energetica India Magazine March - April 2026

For Rayzon, scaling TOPCon to multi-gigawatt levels is less about expansion and more about control. At smaller capacities, inefficiencies are manageable. At 5–10 GW scale, the same inefficiencies directly affect output, cost, and reliability in a signif - icant way. The shift from P-type to N-type in solar manufacturing is already underway, and TOPCon has emerged as the most prac- tical path for large-scale adoption. But there is a difference between installing TOPCon capacity and actually running it efficiently at scale. That difference is where most of the complexity lies. For a company like Rayzon, scaling TOPCon to multi-gigawatt levels is less about expansion and more about con- trol. At smaller capacities, inefficiencies are manageable. At 5–10 GW scale, the same inefficiencies directly affect output, cost, and reliability in a significant way. TOPCon cells require the formation of an ultra-thin tunnel oxide layer, typical- ly in the range of 1–2 nanometers. This layer is critical because it allows elec- trons to pass while reducing recombina- tion losses. The challenge is that maintaining this level of precision consistently across mil- lions of wafers is not easy. Even slight deviations in thickness or contamination during processing can reduce cell perfor- mance. When production runs into giga- watts, these small variations turn into measurable losses. This is why process control becomes central. In TOPCon manufacturing, the margin for error is smaller than in PERC. Temperature uniformity, depo- sition quality, and surface cleanliness all have to be tightly managed. It is not enough to achieve high efficiency once; the factory must deliver the same output across every batch. That is what defines real scale. Another critical factor is yield. Yield is the percentage of good output com- pared to total production. In TOPCon lines, yield losses can come from multi- ple points—wafer breakage, non-uni- form passivation, metallisation defects, or contamination. At a few hundred megawatts, yield losses are tolerable. At multi-GW scale, even a small drop in yield can increase cost per watt and reduce margins. This makes yield man- agement one of the most important op- erational priorities. Equipment plays a role, but it is not the deciding factor. Two factories with simi- lar machines can produce very different results. The difference comes from pro- cess tuning, maintenance discipline, and how quickly issues are identified and cor - rected. TOPCon requires tighter integra- tion between engineering and operations teams because feedback loops need to be faster. Problems cannot be allowed to continue for long production cycles. Material quality also becomes more im- portant. N-type wafers have advantages such as no light-induced degradation, but they require better control during processing. Variations in wafer resistivi- ty or surface condition can affect passiv- ation quality. Similarly, encapsulation materials, glass, and metallisation pastes need to be con- sistent. Any fluctuation in input quality shows up directly in output performance. This is one reason why manufactur- ers scaling TOPCon often move toward backward integration—to reduce depen- dence on external variability. Module design is also evolving along with cell technology. Larger formats like 210 mm or 210R are being used to increase Rayzon: Scaling N-Type TOPCon Manufacturing to Multi-Gigawatt Levels Chirag Nakrani Founder and MD Rayzon Solar Ltd. TOPCON MANUFACTURING 44 energetica INDIA- Mar-Apr_2026