LONGi has recently introduced its newly developed Tera silicon wafers, suitable for currently predominant solar technologies such as TOPCon, heterojunction (HJT) and back contact (BC) cells. These wafers enable an efficiency increase of approximately 0.1% for the aforementioned cell technologies.
The new wafers are the result of three years of intense research and development by a LONGi R&D team of hundreds of employees. LONGi has thus achieved a breakthrough in the field of silicon wafers, in which no significant innovations had occurred in the last decade. The mass market launch is planned for September.
Yichun WangR&D director of LONGi’s wafer division, cites three key advantages of Tera silicon wafers:
- High compatibility with various platforms (TOPCon, heterojunction, back contact)
- More evenly distributed resistance
- Effective removal of impurities
Tera wafers will be available in a range of sizes and thicknesses to meet varying market needs.
16% greater flexural strength
In addition to technological advantages, Tera wafers also feature improved mechanical properties. The proven bending strength of LONGi Tera silicon wafers is 16% higher than conventional wafers, ensuring higher break resistance by producing thinner wafers with a lower chance of cell breakage during production .
Monocrystalline silicon wafers have always been the pioneering products of LONGi, which has achieved the world’s largest shipment volume for nine consecutive years. In recent years, the wafer segment has witnessed the upgrade to large, thin, monocrystalline wafers, and LONGi has contributed significantly to each technological change.
Silicon ingots have a more uniform resistance distribution
The new Tera wafers and their advantages are the result of an improved Czochralski Recharge (RCz) process used in the production of monocrystalline silicon ingots.
The longer conventional silicon ingots are, the greater the difference in resistance across the entire ingot. Thanks to the improved RCz process, LONGi Tera silicon wafers can achieve more uniform axial resistance distribution without having to shorten the ingot length. For the same ingot length, the resistance ratio between the ends is reduced by half, resulting in more efficient cells.
Additionally, metal impurities from LONGi’s Tera silicon wafers can be removed more easily. Compared with conventional products, there are also more possibilities to improve efficiency. The more contaminants that can be removed, the greater the potential for improving cell efficiency.
Improving silicon wafers is essential to improve solar cells
In the last decade, the solar industry has made significant advances in terms of technology and cost. As a result, solar power generation has become the fastest growing source of renewable energy in the world. Global solar power generation entered the “terawatt era” in 2023.
Zhenguo Li, founder and president of LONGi, said that the rapid development of the photovoltaic industry is mainly due to the continuous reduction of electricity costs. Reducing costs and improving the efficiency of power generation are always the driving factors of the photovoltaic industry.
The rapid development of the photovoltaic industry has also accelerated that of silicon wafers, essential for improving solar cells. The quality of the silicon wafer determines the conversion efficiency of the cell. However, in recent years, the continuous improvement of silicon wafer production technology has slowed down the progress of silicon wafer performance improvement. The homogenization of silicon wafer products has become increasingly evident.
LONGi continues to focus on continuous research and development to further improve the performance of silicon wafers and meet the demand for high-quality wafers for today’s need for high-performance solar cells.
Chairman Zhenguo Li said: “We believe in the importance of science, technology and innovation in the PV industry and are focusing our resources on driving improvements to develop more efficient and reliable products to increase solar energy productivity.”
