Chinese Team Designs Lead-free, Eco-friendly Solar Cells

SHANGHAI, (UrduPoint / Pakistan Point News / WAM - 18th Oct, 2025) Chinese scientists have created a tin-based solar cell that rivals the efficiency of conventional lead-based models while eliminating environmental and health risks, marking a significant advance for green energy.

The breakthrough, published in Nature, could accelerate the adoption of perovskite photovoltaics, a next-gen battery technology, in everyday applications.

Perovskite solar cells have been hailed as a potential game-changer for their high efficiency and low production costs, but their reliance on toxic lead has raised concerns about large-scale deployment.

Now, a team led by those from Fudan University has developed a lead-free alternative that achieves a record-breaking power conversion efficiency of 17.7 percent, the highest known level for such cells to date.

"Our goal was to create a solar cell that is truly green throughout its lifecycle," said Liang Jia, the study's co-corresponding author. Tin offers an ideal solution since it is "abundant, safe, highly compatible with solar energy conversion, and easy to manufacture at scale.

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Since tin ions oxidise easily and the interface between layers tends to be unstable, early tin-based cells struggled to reach 10 percent efficiency.

Liang's team redesigned the buried interface by introducing a molecular film to form a homogeneous interfacial layer with well-matched energy level alignment.

This approach helps create a "superwetting" underlayer that guides the growth of uniform, high-quality tin-based perovskite films with reduced defect density, according to the study.

In terms of material cost, tin-based solar cells are theoretically much cheaper than their silicon counterparts, said Liang.

Looking ahead, this green photovoltaic technology is expected to be widely deployed in building-integrated photovoltaics, wearable energy devices, vehicle rooftops, and off-grid clean-power systems.

This technology is especially well-suited for energy applications that involve close human contact, explained Liang.