Researchers Developed Indium-Free Solar Modules
New tin-based tandem solar technology has achieved high efficiency while avoiding rare, expensive materials.
Updated on Sept. 24, 2026 in Energy
Live Poll
Do you trust that new, cheaper materials in solar panels will be as durable as traditional ones?
Scientists have engineered a tandem solar module using tin oxide electrodes that achieved a 31.0 percent efficiency rating. This breakthrough offers a viable alternative to indium, a material that is difficult to source because it is typically produced as a byproduct of zinc refining.
Why it matters
Reducing reliance on indium and silver helps manufacturers bypass supply chain volatility and high costs in the competitive renewable energy sector. By adopting more abundant materials like tin, the industry can better scale production to meet global clean energy demands.
The 32-square-inch minimodule reached 31.0 percent efficiency, while smaller-area cells hit 33.2 percent using reactive plasma deposition. These devices retained 65 percent of their peak efficiency after 105 days of continuous outdoor testing.
The details
Researchers utilized reactive plasma deposition to apply a dense film of tin oxide, avoiding the high-energy particles of conventional sputtering that often damage fragile perovskite interfaces. This process creates a stable architecture that replaces the industry standard of using rare, expensive indium-based electrodes.
Timeline
The indium-free minimodules demonstrated 65 percent efficiency retention over the past 105 days of outdoor operation.
Global silver markets have experienced a deficit for each of the past 6 years.
Photovoltaic silver demand is projected to fall by 19 percent during the current year.
The Big Picture
This development shifts the trajectory of perovskite tandem solar cells by proving that complex, high-efficiency architectures do not require rare, supply-constrained materials like indium. It effectively replaces a legacy dependence on indium-based electrodes with a more sustainable, cost-effective alternative.
This technological advancement could lead to cheaper solar panels by removing the need for rare earth metals in the production process. As manufacturers adopt these cost-effective materials, consumers may eventually see lower prices for residential and utility-scale solar installations.
The takeaway
The move toward tin-based electrodes highlights a growing shift in the solar industry toward using abundant, low-cost materials. Advancing these alternatives is critical for decoupling renewable energy growth from the unpredictable supply chains of rare metals.
Further reading
For more on the latest developments in renewables, explore our Energy section.
Source note: This article includes information reported by Ecoportal.
Live Poll
Do you trust that new, cheaper materials in solar panels will be as durable as traditional ones?
