The Era of Quarter-Cut TOPCon Cells: Laser Cutting and Edge Passivation

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Why Now? Terawatt-level Manufacturing Drives Quarters Solution

As the global manufacturing ecosystem in the solar sector steadily progresses towards the terawatt level, the development of solar cell and panel technologies has entered a profound phase of high precision and systematic integration across the value chain. The dynamics of the industry in 2026 show that improving the performance of key cellular structures, particularly N-type TOPCon cells, is no longer dependent on a single technical breakthrough, but is largely linked to a complete alignment of the value chain, starting with chip manufacturing and crystal growth.

In this context, and to continue to push the boundaries of conversion efficiency while maintaining cost balance, laser cutting technology has emerged to four-quarters, represented by the design of 264 pieces, with the associated edge passivation technology, as a central technology platform to raise the efficiency of TOPCon cells in 2026.

The wide spread of the quadrant structure has deep physical and electrical logic. As chip sizes almost inevitably move towards the size of the G12, i.e. 210 mm, and into the rectangular G12R, the internal current generated by operating large-area chips at full load is very high. In conventional full-cell or half-cell panels, this high current results in significant losses in serial resistance within the binding and packaging structure.

According to Joule’s law of solid physics and electrical circuit theory:

Loss capacity I2R

That is, the resistive heat loss in a given area of the board is proportional to the square of the current passing in that area. When a full-size TOPCon cell is divided into four thin longitudinal segments using high-precision laser cutting, the current passing in each of the quarter’s main conductors is theoretically reduced to a quarter of its original value. Assuming that the resistance of the R-link remains almost constant, the local heat loss caused by joules is reduced to one-six of sixteenths compared to the whole cell.

This effect, the “downscaling to reduce loss” caused by the physical division of space, gives the quadrant technology an advantage that neither half- or three-way technologies can reach when seeking to raise the absolute power of the solar panel.

At the industry chain level, technologies in 2026 are trending as follows:

In flake rings and crystal growth, there is a deeper alignment between the value chain, and a clear trend towards ultra-thin flakes, with tighter carbon footprint control and energy consumption. The thickness of the flakes moves towards 110130 m, with very strict requirements for the purity of the material.

In the cell infrastructure, the boundaries between key technologies are less clear, with a greater focus on interface passivation and metal improvements. TOPCon remains the main industrial base, but borrows from BC and HJT technologies some material and process solutions.

At the plate design level, the innovation is geared towards increasing the density of cell division, maximizing the effective space for electricity generation, and reducing the dependence on silver for bonding. Key features include: multi-piece design, especially quadrants, high-density or gapless packaging, and the introduction of zero-key connectors structure 0BB.

Panel materials tend to be more closely related to the selection of materials and cell structure, with greater customization depending on the usage scenario. This includes improved packaging film, glass and sealing techniques, to suit BIPV or lightweight panel applications in harsh environments.

But while the quadrant technology reduces resistance losses significantly, it also reveals a fatal electrical defect: doubles the area of exposed edges created by the cut. A physical cut inevitably destroys the original chemical passivation layers on the chip surface, introducing deep mesh defects and thermal stresses into the cut surface. This creates the risk of extreme FF decline and Voc effort.

Within this equation between “physical yield” and “material damage,” edge passivation technology has historically propelled to the heart of mass production.

Quadrant technology, with zero key connectors 0BB, high density gapless packaging, and thinning of chips, forms a deep system-wide collaboration system. These technologies are not simple substitutes for each other, but rather a precise division of roles and mutual performance enhancement.

Moreover, industry experts’ judgment suggests that the systemic utility of the quadrant technology for “hot-spot security” has long been undervalued. The innate physical protection mechanism of low current is now being repriced as extreme weather conditions become more frequent.