US 9130074

Patent Summary: US 9,130,074

Date: April 26, 2026

A concise summary of US Patent 9,130,074 is provided below, including details of ongoing litigation involving the patent.

Title: High-efficiency solar cell structures and methods of manufacture.

Assignee: The current assignee is First Solar, Inc. The original assignee was Tetrasun Inc.

Inventors: Oliver Schultz-Wittmann, Denis DeCeuster.

Filing Date: April 21, 2010.

Issue Date: September 8, 2015.

Abstract: The patent discloses various solar cell compositions that generally include a central substrate, along with one or more conductive layers, antireflection layers, and passivation layers, as well as electrodes. It describes multifunctional layers that combine properties such as passivation, transparency, and sufficient conductivity for vertical carrier flow. The patent also covers manufacturing methods, including single-side Chemical Vapor Deposition (CVD) processes and thermal treatments for layer formation and conversion.

Plain-Language Overview of Independent Claims

This patent contains eight claims, with claim 1 being the sole independent claim.

Claim 1: This claim outlines a method for fabricating a solar cell. The process starts with a silicon wafer and involves depositing or growing electrically passivating interface layers on both its front and back surfaces. Following this, electrically passivating and conductive film layers are deposited over these interface layers. A crucial step is a thermal treatment at a temperature of at least 500°C. The claim specifies that this heat treatment is designed to achieve one or more of the following: crystallize an amorphous silicon-containing compound into a polycrystalline film, enhance the optical transmissivity of the film, activate doping atoms within the film, and/or cause dopant atoms to diffuse into the silicon wafer to create a p-n junction or a high-low junction. The final step is adding metal electrodes to the structure.

Litigation Update

As of early 2026, US Patent 9,130,074 is the subject of significant legal action. First Solar, Inc. has initiated an investigation through the U.S. International Trade Commission (ITC) into Tunnel Oxide Passivated Contact (TOPCon) solar products. The investigation targets numerous companies, including major solar manufacturers, for alleged infringement of this patent.

First Solar acquired the patent through its 2013 purchase of TetraSun Inc. The company has filed lawsuits in the United States District Court for the District of Delaware against JinkoSolar and Canadian Solar, among others, for alleged infringement of the '074 patent. In January 2026, the U.S. Patent and Trademark Office (USPTO) denied petitions filed by JinkoSolar, Canadian Solar, and Mundra Solar that sought to invalidate this and a related patent, strengthening First Solar's position in the ongoing litigation. This patent is central to First Solar's efforts to protect its intellectual property related to TOPCon solar cell manufacturing technology.