SiOnyx Solar achieves record results for Black Silicon solar cells

BEVERLY, USA: SiOnyx Inc. announced that its patented ultrafast laser texturing technology known as Black Silicon has achieved a 0.3 percent (absolute) efficiency boost over industry-standard baseline solar cells. The SiOnyx 156 mm multicrystalline silicon cells, made in collaboration with German research institute ISC Konstanz, achieved average absolute efficiencies of over 17 percent.

Importantly, SiOnyx Black Silicon boosts efficiency in thinner wafers, vital for reducing the cost of silicon-based solar cells. Average efficiencies of 16.9 percent were achieved for 150-micron thick multicrystalline cells that are 20 percent thinner than wafers in production today and represent a cost reduction of 10-15 percent. All cells were processed and tested at ISC Konstanz using a standard emitter, screen-printed metal, and aluminum back surface field. Black Silicon texturing was performed using a Coherent Aethon tool with a Talisker picosecond laser.

Additionally, the SiOnyx process results in a significant improvement in process uniformity. Standard deviations for cell efficiency and current are reduced by a factor of two using SiOnyx's Black Silicon, resulting in further cost reductions through improved process yield and tighter efficiency binning.

"These results are further validation of the Black Silicon process and its ability to improve the economics of mainstream solar energy - and the technology is ready now," commented Stephen Saylor, president and CEO of SiOnyx.

"SiOnyx's single-sided texture achieves significantly lower surface reflectance than industry-standard isotexture to improve cell performance. We boost infrared performance, thus making SiOnyx Black Silicon a great complement to existing selective emitter technologies."

SiOnyx Black Silicon is a drop-in solution for the majority of solar cell lines using industry standard isotexture and is critical in supporting roadmap architectures requiring a planar back surface for dielectric passivation. SiOnyx Black Silicon is completely independent of grain orientation and therefore ideal for all wafer types including multicrystalline.

By decoupling the saw damage removal and surface texturing steps, the SiOnyx process is the perfect solution for manufacturers seeking to improve both the price and performance of existing lines while establishing a roadmap for next-generation cells using backside passivation with local contacts.