First Solar has secured a significant legal win in the ongoing intellectual-property battle over Tunnel Oxide Passivated Contact (TOPCon) solar cell technology patent. The United States Patent and Trademark Office (USPTO) rejected multiple attempts by competitors JinkoSolar, Canadian Solar and Mundra Solar to invalidate key patents held by First Solar that cover methods fundamental to high-efficiency crystalline silicon cell manufacturing. The decision also preserves First Solar’s patent rights as it pursues infringement litigation in federal court.

More on First Solar Major Key Round Win in Global TOPCon Dispute

First Solar has also concurrently filed infringement lawsuits in the U.S. District Court for the District of Delaware against the same patent competitors. The American solar modules manufacturer is alleging unauthorized use of the patented technology in commercial solar cell production in facilities like Canadian Solar’s Mesquite in Texas. The geographic scope of First Solar’s rights also broadens as licensed counterparts of the TetraSun patents also exist in other major markets including China, Japan and the EU.

First Solar TOPCon Patent Fight and the Global PV Market

USPTO decision is not only a win for First Solar on the production line but also in the markets as it strengthens the company’s ability to enforce its TOPCon patent portfolio and pursue monetary and injunctive relief against its competitors. The American solar panels manufacturer has production facilities in Louisiana and Ohio, and is currently building a new one in South Carolina.

TOPCon technology is widely adopted by major crystalline silicon manufacturers. The technology thus represents a large and rapidly growing segment of solar cell production globally. Additionally, by preserving its patent rights, First Solar is not only taking a better bargaining position in licensing negotiations (such as the earlier agreement with Talon PV, a U.S. cell maker) but also creating leverage in ongoing and future disputes as newer technologies supersede legacy ones.

Outlook on First Solar’s Legal Dispute

First Solar’s fight over TOPCon patents is likely to continue in multiple legal avenues. This include the ongoing Delaware litigation. Preserving the validity of its patents at the USPTO also hastens timeline for U.S. court judgments and could potentially lead to settlements or licensing deals with the named competitors who are also significant players in the global PV supply chain.

First Solar’s TOPCon patent case also highlights a trend in cleantech where intellectual property is increasingly consequential. This is not only in terms of competitive differentiation but also in shaping industry structure and capital allocation.

First Solar TOPCon Patent Factsheet

Technology: Tunnel Oxide Passivated Contact (TOPCon) solar cell technology

Key Patents: U.S. Patent No. 9,130,074 and U.S. Patent No. 9,666,732

Case Decision: USPTO denies challenges to patent validity from JinkoSolar, Canadian Solar and Mundra Solar

Ongoing Legal Cases: Infringement litigation in U.S. District Court for the District of Delaware

Patent Origins: Acquired through First Solar’s 2013 purchase of TetraSun

Impact on the Solar PV Markets: Strengthens First Solar’s licensing power and infringement position across key solar PV global markets.

Development Timeline

2013: First Solar acquires TetraSun and its patent portfolio covering TOPCon cell technology.

2015 to 2017: Key TOPCon patents are issued in the U.S. and related jurisdictions.

2024: First Solar begins warning competitors about alleged unauthorized use of TOPCon patents.

2025: Multiple IPR petitions filed by JinkoSolar, Canadian Solar and Mundra Solar seeking to invalidate First Solar’s patents.

Late November to December 2025: USPTO Director denies IPR petitions.

Jan 2026: Infringement litigation continues.