GCL System Integration Technology Co., Ltd. (GCL-SI) has raised its self-developed Passivated Emitter Rear Cell (PERC) solar cell average efficiency to 20.1% in mass production by utilizing Reactive Ion Etching (RIE) technology, with the highest test reaching 20.6%. It marks a major step forward in advancing the efficiency of multi-crystalline cells.

Black silicon is well-known for its particularly useful properties, such as extremely low reflectance and weakly low absorption of some kinds of photons, for photovoltaic applications. Meanwhile, the main barrier for the introduction of diamond wire sawing of mc Si into mass production is the difficulty to texture using typical industrial acidic texturing method. Fortunately, nanostructured black Si can effectively resolve this issue. In this regard, GCL-SI has taken the lead in the integration of all three existing methods – additive direct texturing, metal assisted chemical etching (MACE), and RIE -- thus making massive manufacturing a reality in terms of cost reduction and efficiency gain.

"We have now effectively resolved the issue of multi-crystalline PERC cell degradation and power loss. Through proper regeneration annealing processing, an additional absolute efficiency gain up to 0.15% can be reached. Furthermore, the LID results show properly treated cells have significant improvement in degradation behavior with less than 1% relative efficiency loss," said Dr. Zhang Chun, head of GCL-SI's R&D cell team. GCL-SI's progress comes from its huge investment in solar cell innovation. Leveraging its expertise in photovoltaic technology, it has established a special R&D team dedicated to black silicon to explore ways to minimize costs and fully tap its potential.

Having already begun the process in February, which has achieved average cell efficiency of 20.1%, GCL-SI will continue its efforts to scale up the mass production of PERCs. As Dr. Zhang put it, "GCL-SI will further advance towards the goal of realizing an average efficiency of 20.5% and a maximum efficiency of somewhere between 20.8% and 21% in 2017."

GCL-SI is geared up for more breakthroughs that will provide the market with the highest quality, highest efficiency solar cells and equipment at a substantially lower cost. "With more advanced technology, we hope to make solar energy more efficient and bring it to more markets around the world," said James Hu, president of GCL-SI Overseas BU.