Key takeaways:
JTPV presented its Cut Line Technology (CLT) as an additional approach to reduce cut-edge losses in TOPCon cells
The process selectively removes the emitter near cut regions before passivation, helping improve fill factor and module power
The company also highlighted process optimization for improved UV reliability with lower degradation from UVID under testing
As TOPCon module layouts move toward multi-cut designs, manufacturers are also exploring process routes beyond edge passivation to address cut-related recombination losses. Jietai Solar (JTPV) found an approach that can work independently and complement edge passivation. The company calls it Cut Line Technology (CLT), which the company’s R&D manager, Xinrui An, discussed in detail at the TaiyangNews High-Efficiency Solar Technologies Conference 2025.
JTPV’s solution is designed to address the damage most pronounced in the immediate vicinity of the emitter region. One effective mitigation strategy is to selectively remove the emitter at the laser-cut positions. Following this approach, the emitter is removed locally immediately after its formation. The resulting exposed front surface is then cleaned and passivated with aluminum oxide and silicon nitride layers as part of the subsequent cell processing. The local polished surface, though, has higher reflectance, given the fractional area it represents in the cell’s active area – 300 μm per line and 1 mm for 3 lines required for a 1/4th cell layout, it has a negligible impact on the cell efficiency. The line width can be adjusted if the module makers need a larger tolerance for laser cutting. The main benefit of CLT is reflected as gains in fill factor and power. The power gain from CLT alone (without edge passivation) is about 3 W for a half-cell, all the way up to 8 W for a quarter-cut reference, which are also not edge treated. This gain is brought about not only by an increase in the number of cuts but also by the narrower slices, as the edge effect becomes more profound within each slice, according to An. The technology is compatible with any cell format, and it offers good edge isolation for module suppliers that can only process full cells. It can also be combined with edge passivation, resulting in about a 5 W power gain over the edge-passivated baseline, says An.
While not as prominent as edge passivation or CLT discussed above, companies are also working on a couple of incremental developments. JTPV, for example, detailed its experience in optimizing UV stability – a small sacrifice in Voc and Isc for better UV reliability. According to An, the company opted for a paste that is not optimized for contact recombination but offers good damp-heat reliability. The resultant cells have lower Voc but higher fill factor. This also led to a slightly higher temperature coefficient. However, in comparative testing of UV-induced degradation (UVID), JTPV modules show significantly lower degradation rates of around 0.3-0.4%, compared to approximately 2% observed in competing products after 10 months of operation.
The text is an edited excerpt from TaiyangNews’ report on Cell & Module Technology Trends 2026, which can be downloaded for free here.