The US International Trade Commission has launched a Section 337 investigation into certain imported tunnel oxide passivated contact solar cells,modules,and associated products.The case is registered under number 337-TA-1494.This follows a patent infringement complaint submitted by First Solar on 24 February 2026,which alleges breaches of Section 337 of the Tariff Act of 1930.

A total of 47 respondents have been named,including manufacturers and their subsidiaries operating in the United States,China,India,Vietnam,Japan and Germany.The list includes leading PV enterprises such as AXITEC,Canadian Solar,JA Solar,JinkoSolar,Trina Solar,Adani Green Energy,Hanwha Q CELLS,Runyang,T1 Energy,Vietnam Sunergy,VSUN and Toyo.

First Solar has petitioned for a general or limited exclusion order,as well as cease-and-desist orders,to restrict the sale and distribution of the relevant products within the US market.Respondents must submit their response within 20 days of being notified;otherwise,the commission may issue the requested orders by default.

An administrative law judge will deliver a preliminary ruling on the alleged violations,after which the full commission will conduct a review and make a final determination.The USITC will establish a target completion date within 45 days.Any remedial order will take immediate effect,although the United States Trade Representative retains the authority to veto such an order within 60 days.

If a ruling on infringement is confirmed,it could result in a near-complete ban on TOPCon solar imports,which would intensify existing volatility in global photovoltaic supply chains.

First Solar’s intellectual property claims over certain TOPCon technologies originate from its acquisition of TetraSun in 2013.The firm has previously initiated patent litigation against Adani,Canadian Solar,and JinkoSolar.In January 2026,the United States Patent and Trademark Office rejected inter partes review applications filed by these three companies against First Solar’s relevant patents.