Hanwha Q-Cells’ US PERC Solar Cell Patent Invalidated

On June 28, 2021, the Patent Trial and Appeal Board of the U.S. Patent and Trademark Office (USPTO) issued a final written decision on an inter partes review (IPR) proceeding, declaring all of the patent claims in Hanwha Q-Cells’ U.S. Patent 8,933,525B2 to be invalid. The patent attempts to cover a specific type of PERC solar cell with a three-layer passivation structure, including a chemical passivation layer, a field-effect passivation layer, and a silicon nitride cover layer. The field-effect passivation layer contains aluminum oxide. Although this patent has been filed and was granted in many countries previously, it was considered to be obvious and not novel based on the analysis of LONGi’s IP team, which filed an invalidity procedure with evidence in a number of countries. The USPTO agreed with LONGi that all of the claims in Hanwha Q-Cells’ patent do not fulfill several legal requirements and are unpatentable.


This decision is welcome news for LONGi and also for the industry. It follows LONGi’s earlier success in invalidating another Hanwha Q-Cells solar cell patent, US 9,893,215B2, in another IPR proceeding. That was initiated after Hanwha Q-Cells filed a suit against LONGi at the US International Trade Commission (USITC) in 2019.



LONGi respects legitimate intellectual property rights, and understands that valid patents play an important role in technological progress. At the same time, invalid patents, and attempts to enforce such patents, negatively affect both the industry and the enterprises involved.


Accordingly, LONGi will continue to resist baseless assertions of patent infringement and will continue to invest in the fight against invalid patents.