Longi Breaks Theoretical Limit: Solar Cells Reach 34.85% Efficiency

Chinese solar giant Longi has shattered expectations with a new tandem solar cell that achieves a record-breaking 34.85% efficiency—thanks to an innovative fusion of perovskite and silicon technologies.

In the world of solar energy, even a 0.1% boost in efficiency is considered a big deal. Now imagine surpassing what was long believed to be the absolute theoretical ceiling—by more than a full percentage point. That’s exactly what Longi accomplished with its latest silicon–perovskite tandem cell, certified by the prestigious U.S. National Renewable Energy Laboratory (NREL). The achievement marks not just a new world record, but a major milestone in the evolution of photovoltaic science.

How Did They Do It?

The secret lies in a carefully engineered blend of materials, including lithium fluoride, a molecule known as ethylenediammonium diiodide (EDAI), and an asymmetrically textured silicon surface. Sound technical? Let’s simplify.

Breaking the Unbreakable: Longi vs. Shockley-Queisser

For decades, the Shockley–Queisser limit of 33.7% was regarded as an almost unbreakable wall for single-junction solar cells—a theoretical boundary set back in the 1960s. It became the “Holy Grail” of solar efficiency.

Now, Longi has gone beyond it—achieving a 34.85% conversion rate. In solar terms, that’s the equivalent of shaving half a second off a world record sprint. And the trick? Combining conventional silicon—the base of 95% of today’s solar panels—with perovskite, a newer material with extraordinary light-absorbing properties.

Material Innovation: The Real Magic

The breakthrough lies in the layered cell structure. Longi’s engineers enhanced both the hole-blocking (positive charge carriers) and electron transport processes by integrating ultra-thin layers of LiF and EDAI.

Think of it as designing a perfectly paved expressway for electrical particles: EDAI patches areas where LiF alone wouldn’t be effective, resulting in smooth, efficient charge movement throughout the cell.

Perhaps most impressively, Longi addressed one of the trickiest challenges in tandem cell design—how to connect different materials efficiently. Their asymmetrically textured silicon surface provides an elegant solution, improving light capture and interface quality simultaneously.

A Company Built on Breaking Records

This isn’t Longi’s first leap forward. The company has consistently pushed the limits of solar performance. In November 2023, it reached 33.9% efficiency. By June 2024, it climbed to 34.6%. Now, with this latest result, the trajectory is clearly upward.

And their innovation doesn’t stop with tandem cells. Longi also set a new benchmark with a silicon cell using Heterojunction Interdigitated Back Contact (HIBC) technology, reaching an impressive 27.81% efficiency—outstanding for a monocrystalline silicon cell.

What This Means for the Future of Solar

So, why does this matter to the rest of us? Higher efficiency means more energy harvested from the same area, making solar installations more powerful and cost-effective. It could accelerate the shift toward renewable energy in both residential and commercial sectors.

We may be standing at the edge of a new era in solar technology. When companies like Longi defy once-untouchable limits, they unlock possibilities we hadn’t even imagined.

One day, the Shockley–Queisser limit may be remembered not as a barrier, but as a stepping stone—something that inspired a new generation of scientific breakthroughs and cleaner energy for all.

Read the original article on: Futuro prossimo

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