Solar cells get a laser finish that pushes perovskites closer to silicon

A team at Huazhong University of Science and Technology has shattered efficiency records for all-perovskite tandem solar cells, reaching 29.8% with a novel laser polishing technique. The non-contact method targets surface defects in lead-tin perovskite films without physically touching the material—a critical advantage for fragile thin-film devices. According to the researchers, this approach improved the bottom cell's efficiency from 19.64% to 24.07%, while maintaining strong operational stability under continuous illumination.

The breakthrough addresses two persistent bottlenecks in perovskite solar technology: voltage losses and low fill factors. Traditional manufacturing methods often introduce microscopic defects that trap charge carriers, reducing overall performance. By using precise laser pulses to smooth the film surface, the team effectively minimized these defects without compromising the material's structural integrity.

PV Magazine reports that the polished cells retained 90% of their initial efficiency after 1,000 hours of testing, a significant milestone for commercial viability.

The source material also shows that this efficiency leap brings perovskite solar cells closer to competing with silicon-based panels, which currently dominate the market with efficiencies around 22-24%. The laser polishing technique could also reduce manufacturing costs by eliminating the need for additional chemical treatments or protective layers. However, challenges remain before widespread adoption.

Scaling the process for industrial production will require precise control over laser parameters to avoid damaging the delicate perovskite layers.

The research highlights the potential of tandem architectures, where multiple layers of perovskite absorb different parts of the solar spectrum. While the 29.8% efficiency is impressive, real-world deployment will depend on long-term stability and cost-effectiveness. If these hurdles are overcome, laser-polished perovskite cells could redefine solar energy economics, particularly in space-constrained applications like urban rooftops or electric vehicles. The team plans to further optimize the laser parameters and explore roll-to-roll manufacturing to accelerate commercialization.