Chinese Team Sets Stability Record for Tin Perovskite Solar Cells

• Chinese researchers have unveiled a nucleation-layer technique that boosts tin perovskite solar-cell efficiency to 11.18 % and preserves 95 % output after 2,700 hours in air.

A consortium of scientists from Sichuan University, Zhejiang University, the Chinese Academy of Sciences and Guangxi University says it has cracked one of the biggest obstacles facing next-generation tin perovskite solar cells: oxygen instability.

In a peer-reviewed paper released this week, the group details a “nucleation-layer assisted” (NLA) manufacturing step that reshapes how the perovskite layer grows, delivering both higher power output and record-setting durability. Tin perovskites are widely viewed as a promising, lead-free route to cheaper photovoltaic panels, but they have been hamstrung by rapid degradation when exposed to air.

The team’s solution is disarmingly simple. After spinning a standard perovskite layer onto a glass substrate, researchers rinse it off and then briefly anneal the microscopic residue that remains. That skinny “ghost coating” becomes a seed-crystal template for the next perovskite layer.

When fresh precursor solution is deposited, the film no longer grows as a jumble of random grains. Instead, it self-organises into a tidy, vertically aligned stack of so-called Ruddlesden–Popper phases with intermediate “n values” that are less vulnerable to oxygen infiltration. The resulting surface resembles overlapping slate tiles—tight, uniform and largely free of pinholes.

Electrical tests show the reorganised film moves charge more efficiently, binds excitons less strongly and dampens the electron-phonon interactions that sap performance. Most importantly, oxygen molecules struggle to penetrate the close-packed lattice. In laboratory trials, an unencapsulated cell retained 95 % of its initial efficiency after 2,700 hours in dry air—roughly four times longer than previous tin-based records.

While the champion device posted a modest 11.18 % power-conversion efficiency, the authors insist the figure can rise quickly because the NLA step relies on tools already standard in thin-film production lines. Scaling should therefore require little more than recipe tweaks rather than new capital equipment.

If follow-up work confirms those claims, tin perovskites could move from niche curiosity to mainstream contender, offering a non-toxic rival to today’s lead-based perovskite cells and potentially undercutting conventional silicon on cost per watt.