#China #Risen Energy #Ningbo #HJT Technology #Ultra-Thin Wafers

Introduction

In an era where sustainable energy is at the forefront of technological advancement, Risen Energy is making waves in the photovoltaic sector with its groundbreaking work on ultra-thin silicon wafers. As the industry turns its gaze toward possibilities in space photovoltaics, the discourse surrounding lightweight design, high-power output, and extraordinary durability is gaining traction. Central to Risen Energy's innovation is the development of ultra-thin wafers utilized in its Heterojunction (HJT) solar cells, which is set to redefine energy generation both on Earth and beyond.

The Case for Ultra-Thin Wafers

Risen Energy's journey in developing ultra-thin wafers is detailed in its comprehensive white paper, which highlights not only the technology's development but also its potential applications in mass production. The decision to opt for thinner wafers is a multifaceted one, combining economic incentives with the technical advantages tied to the unique nature of HJT technology. According to the white paper, silicon wafers represent a significant portion (55%) of the cost structure in HJT solar cells, making it vital to explore thickness reduction for cost efficiency. However, it's not merely about saving costs; the structural integrity of the HJT manufacturing process permits a gentler processing method that reduces risks often related to high temperatures, such as warping and breakage, faced by technologies like PERC and TOPCon.

Balancing Efficiency and Reliability

Risen Energy has navigated the complex relationship between wafer thickness, efficiency, and mechanical strength. Their investigations reveal a compelling interplay: as wafer thickness decreases, short-circuit current (Jsc) tends to drop, yet open-circuit voltage (Voc) tends to rise. The fill factor remains steady, resulting in an overall efficiency gain, especially at optimized thickness levels. Currently, Risen Energy's HJT Hyper-ion cells, utilizing 110 μm wafers, achieve an impressive average efficiency of 26.4%, with some production lots exceeding 26.6% efficiency. This success underscores that well-managed thinning processes can enhance performance rather than hinder it.

Innovation in Manufacturing Processes

To complement the scientific advancements in wafer technology, Risen Energy has reengineered its manufacturing processes. The switch from horizontal to vertical wafer cassette configuration improved yield rates significantly, achieving over 99.5% stabilization in production with fragment rates below 0.25%. Moreover, rigorous tests show that HJT cells, when reduced to thicknesses below 100 μm, not only maintain flexibility but also permit development into lightweight solar modules, opening new pathways for innovation.

Beyond Earth: Space Applications

For applications in space, where weight is a critical factor, Risen Energy pushes the boundaries further, capable of producing solar cells thinner than 70 μm. The synergy of their ultra-thin wafer technology with the demands for high power-to-weight ratios is revolutionary, potentially setting new performance standards in the aerospace sector.

Addressing Manufacturing Challenges

The manufacturing of ultra-thin cells presents unique challenges, particularly regarding the conventional high-temperature soldering process. In response, Risen Energy has developed the Hyper-link stress-free cell interconnection technology, which circumvents the issues related to thermal stress from soldering. Supported by a robust portfolio of over 50 patents, this innovative approach aligns harmoniously with the low-temperature characteristics of HJT cells, drastically improving reliability. Results from a battery of rigorous tests outstrip the IEC standards designed for durability and performance, confirming Risen Energy’s position at the forefront of the industry.

Integrated Innovation for Future Competitiveness

As Risen Energy reflects on its advancements in ultra-thin wafer technology, it highlights integrated innovation as a driving factor. The seamless collaboration between wafer thinning, low-silver metallization, and new interconnection methods underscores a commitment to systematic innovation. The final product, known as the Hyper-ion, marries efficiency with performance optimally, demonstrating that dedication to technological essence can indeed yield significant advancements.

Conclusion

Risen Energy's pioneering journey into ultra-thin wafers represents not just a move towards cost reduction but also a commitment to enhancing the photovoltaic industry as a whole. By revisiting their foundational white paper, the company hopes to inspire collaboration and innovation across the sector. The vision is clear - a future where photovoltaic technology is not only lighter and stronger but also infused with creativity that reimagines its applications, both on Earth and in the expanse of outer space.