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

The Evolution of Risen Energy: Ultra-Thin Silicon Wafers

Risen Energy is at the forefront of solar technology, particularly in the development of ultra-thin silicon wafers for heterojunction solar cells (HJT). As the discussions around space photovoltaics intensify in the industry, Risen Energy's innovative approach has set it apart. The company has been diligently working on this technology, which not only meets the increasing demand for lighter, more efficient solar solutions but also aligns with sustainability goals.

Understanding HJT Technology and Its Advantages

Heterojunction technology has emerged as a game-changer in solar cells due to its unique manufacturing process, which occurs at low temperatures (below 200°C). This advantage allows for a more delicate handling of the wafers, reducing the risk of deformation or breakage—issues often faced by higher temperature processes like PERC and TOPCon. Risen Energy found that using ultra-thin wafers significantly reduces production costs, as wafer production comprises about 55% of the total cost of HJT solar cells.

Balancing Thinnest with Reliability

The transition to ultra-thin wafers is not merely an economic choice; it represents a systematic balance between efficiency, yield, and mechanical strength. Risen Energy's experiments have shown that while thinning the wafers can reduce the short-circuit current (Jsc), it simultaneously enhances the open-circuit voltage (Voc). Interestingly, the fill factor (FF) remains stable, allowing for acceptable overall efficiency within specific thickness ranges. Advanced production lines have enabled Risen Energy to achieve an average efficiency of 26.4% with its Hyper-ion HJT cells made from 110 μm wafers.

Innovations in Manufacturing Processes

To further optimize the manufacturing process, Risen Energy has revamped its cassette configurations from horizontal to vertical insertions. This shift has increased production efficiency while maintaining a consistently high yield of over 99.5%, ensuring a fragmentation rate of less than 0.25%. Such systematic changes demonstrate that the challenges associated with thinning wafers can indeed be overcome through innovation in process management.

Mechanical Flexibility Amidst Thinness

Another remarkable aspect of thin wafers is their mechanical resilience. Tests have indicated that while thicker PERC (150 μm) and TOPCon (130 μm) cells tend to crack under stress, ultra-thin wafers under 100 μm have exhibited exceptional flexibility. This characteristic opens up new possibilities for lightweight modules and applications in specialized environmental conditions, thereby expanding the usability of HJT technology.

Driving Towards Space Applications

Risen Energy’s current Hyper-ion HJT products utilize silicon wafers of 110 μm and solar cell thicknesses around 95 μm, achieving an optimal balance of cost, efficiency, and reliability. However, the company also aims higher, aiming for applications in space photovoltaics, which traditionally require an incredibly high power-to-weight ratio. Risen is capable of producing solar wafers thinner than 70 μm, precisely the thickness needed for these advanced applications.

The Evolution of Interconnection Technologies

The advent of ultra-thin cells necessitated innovations in interconnection technologies. Risen Energy has developed a patented, stress-free cell interconnection method called Hyper-link, effectively eliminating thermal stress during soldering. This new methodology not only fits well with the low-temperature processing characteristics of HJT technology but also enhances the overall performance of ultra-thin cells.

Conclusion: A Unified Approach Towards Innovation

Risen Energy understands that the journey towards ultra-thin cell production transcends mere technological breakthroughs, requiring an integrated focus from wafers to modules. The synergy between innovations such as wafer thinning, low silver metallization, busbar-free cells, and Hyper-link technology illustrates how these developments come together to bolster the competitiveness of Hyper-ion products. Through continuous learning and improvements, Risen Energy aspires to lead the solar technology sector towards a brighter, more efficient, and sustainable future while reinforcing its commitment to innovation.

In summary, Risen Energy’s ongoing research and practical applications not only demonstrate advanced engineering but also contribute significantly to the evolution of photovoltaic technology, paving the way for lighter and more powerful solar solutions.