Evolution of Wafer Sizes and Technical Standards in Different Generations of the Photovoltaic Industry

In the photovoltaic (PV) industry, designations such as M0, M1, M2, M4, M6, M10, G1, and G12 represent different generations of silicon wafer sizes and associated technical standards. These codes primarily reflect the evolution of wafer dimensions, which directly impact module power, efficiency, and system-level cost. Below is a detailed explanation of each specification:

M‑Series (Monocrystalline Silicon Wafers)

The M‑series denotes the mainstream evolution of emonocrystalline silicon wafer sizs, driven by continuous optimization for higher efficiency and lower manufacturing cost.

1. M0 / M1 / M2 (156.75 mm × 156.75 mm)

These were the early‑generation standard sizes for monocrystalline wafers, widely adopted in conventional multicrystalline and early‑stage PERC monocrystalline modules.

Key distinctions among M0, M1, and M2 lie in minor bevel‑edge variations and cell‑efficiency refinements.

2. M4 (163 mm × 163 mm)

A transitional size between M2 and M6, offering a slight area increase over M2. It did not gain widespread adoption and was soon superseded by larger formats.

3. M6 (166 mm × 166 mm)

Introduced around 2019, M6 provides an area about 12% larger than M2, enabling higher power density. It is fully compatible with most existing module production lines and has been widely used in high‑efficiency PERC and TOPCon cells.

4. M10 (182 mm × 182 mm)

Since 2020, M10 has become the industry mainstream for large‑format modules. With an area approximately 20% larger than M6, it delivers significantly higher module power output and further reduces balance‑of‑system costs. M10 is adopted for advanced cell technologies including PERC, TOPCon, and heterojunction (HJT).

G‑Series (Large‑Format Wafers)

The G‑series represents the trend toward even larger wafer sizes, primarily targeting ultra‑high‑power modules.

1. G1 (158.75 mm × 158.75 mm)

Derived by adding 2 mm to the M2 wafer, G1 was an early attempt to boost module power while maintaining equipment compatibility. It served as a transitional product and has been largely phased out following the rise of M6 and larger formats.

2. G12 (210 mm × 210 mm)

Currently the largest commercially available wafer size, G12 offers an area about 30% larger than M10. Designed for ultra‑high‑power modules (600 W and above), it pushes the boundaries of module performance but requires upgraded production equipment and careful system‑design adaptation.

Key Differences Between M‑Series and G‑Series

1. M‑Series (M0 – M10)

Reflects the steady, incremental expansion of monocrystalline wafer sizes from the early 156.75 mm to today's mainstream 182 mm, balancing performance gains with manufacturing continuity.

2. G‑Series (G1 / G12)

Represents a more aggressive leap in wafer dimensions, notably the 210 mm G12, aimed at maximizing single‑module power output and lowering levelized cost of electricity (LCOE) at the system level.

Industry Trends and Outlook

The progression from M0 (156.75 mm) to M10 (182 mm) and G12 (210 mm) underscores the PV industry's relentless drive toward larger wafer sizes, higher conversion efficiency, and reduced LCOE.

1. Current Landscape: M10 (182 mm) dominates the market for its optimal balance of power uplift and production‑line compatibility, while G12 (210 mm) is expanding in segments that prioritize maximum module power.

2. Future Directions: Further size optimization may continue, but the focus is shifting toward cell‑technology advancement (e.g., TOPCon, HJT, back‑contact) and module‑level innovation (e.g., shingling, tiling, advanced encapsulation) to extract more energy from each wafer.

3. Production Considerations: Larger wafers demand upgrades in slicing, handling, cell processing, and module assembly equipment. Harmonization of standards across the supply chain remains critical for seamless adoption.

Conclusion

The evolution of silicon wafer sizes—from the early M0 to today's M10 and G12—mirrors the photovoltaic industry's pursuit of higher performance and lower cost. While size expansion has been a key lever for progress, the future will increasingly rely on a combination of advanced cell architectures, smarter module design, and integrated system optimization to sustain the momentum of solar energy's competitiveness.

Looking forward, ChinTiyan believe the industry is entering a new phase characterized by "standardized dimensions and diversified technologies." As wafer sizes converge toward established standards, we are accelerating our R&D in N-type TOPCon, HJT, and perovskite tandem technologies. Through this dual approach of "advanced formats + cutting-edge cell architectures," we are committed to delivering higher efficiency, greater reliability, and superior return on investment for our global customers.