Perovskite-silicon triple-junction solar cells achieve record-breaking 30% efficiency

The previous solar efficiency record has now been broken, and this one could have real-world impact. Researchers at EPFL and CSEM have developed a triple-junction solar cell with a certified efficiency of 30.02%.

That pushes past the earlier 27.1% mark and puts a new spotlight on scalable, high-performance designs.

Most record-setting solar cells stay limited to expensive materials or lab conditions.

This device takes a different route. It combines a silicon bottom cell with two perovskite layers built as thin films.

The goal is clear: deliver higher efficiency without making manufacturing impractical.

Record meets real-world

Solar breakthroughs often struggle to move beyond prototypes.

This result stands out because it targets both performance and scalability.

Kerem Artuk, the study’s first author, explained the significance.

“We show that with clever design and processing, we can approach performance levels traditionally reserved for the most expensive III–V multi-junction solar cells used in space, which are composed of multiple semiconductor layers.”

He added that these cells “can reach up to 37% efficiency, and cost around 1,000 times more than terrestrial cells per watt.”

“Our approach opens the door to a new generation of industrially viable, high-efficiency multi-junction photovoltaics.”

That distinction matters for the US solar market. Higher efficiency reduces the number of panels needed for the same output. It also improves returns for both rooftop and utility-scale projects.

Fixing known weak spots

Triple-junction designs promise strong performance, but they come with technical challenges.

The EPFL team focused on two key issues: low voltage in the top cell and weak current in the middle layer.

They introduced a molecule that improves how perovskite crystals form. This step reduces defects and raises voltage in the top cell to 1.4 volts under sunlight.

The middle layer uses a new three-step fabrication method. It improves absorption in the near-infrared range, which carries a large share of solar energy.

The team also added nanoparticles between layers. These particles reflect light back into the middle cell and increase current.

Christophe Ballif highlighted the pace of progress. “Our first demonstration in 2018 had only 13% efficiency, so reaching over 30% efficiency today in a triple-junction device is a remarkable achievement.”

He added, “Triple-junction solar cells have an even higher efficiency potential compared to single junction and tandem – well above 40%.”

Cost remains the biggest barrier for high-efficiency solar cells. III-V semiconductors deliver strong performance but remain too expensive for widespread use.

This new design uses silicon and perovskites, both more affordable and easier to scale.

That combination could make high-efficiency panels more viable across US homes and solar farms.

Christian Wolff pointed to the broader implications.

“This project illustrates the power of combining fundamental science with Swiss engineering know-how,” he said.

“By demonstrating that low-cost perovskite materials can approach the performance of the most advanced space-grade photovoltaics, this research sets a new benchmark for multi-junction photovoltaics.”

The team now plans to focus on durability and large-scale production. If those efforts succeed, this record could translate into practical solar deployments sooner than expected.

The study is published in the journal Nature.