LONGi Shatters Solar Efficiency Record with 35.5% Perovskite-Silicon Tandem Cell

Mon, 20 Jul 2026 00:00:00 +0000

Chinese solar manufacturer LONGi has achieved a groundbreaking 35.5% conversion efficiency for its crystalline silicon-perovskite tandem solar cell, marking another leap forward in photovoltaic technology. The result was independently verified by the European Solar Test Installation (ESTI), a reference laboratory for solar cell calibration based in Ispra, Italy.

The announcement represents the latest milestone in a rapid progression of efficiency records for LONGi, which has been steadily pushing the boundaries of tandem solar cell technology. The company first achieved 33.9% efficiency in November 2023, followed by 34.6% in June 2024, before reaching the current 35.5% benchmark through a series of incremental improvements.

Photovoltaic solar panels in a field. LONGi’s new tandem cell pushes well beyond current commercial panel efficiencies.

How Perovskite-Silicon Tandem Cells Work

Traditional silicon solar cells — the kind found on most residential and commercial rooftops — are approaching their practical efficiency limits. According to the U.S. Energy Information Administration, commercially available panels now hover around 25% efficiency, getting close to the theoretical single-junction Shockley-Queisser limit.

Perovskite-silicon tandem cells solve this problem by stacking two light-absorbing layers atop one another. The top perovskite layer captures high-energy photons (blue and green light), while the bottom silicon layer absorbs lower-energy photons (red and infrared light). This dual-layer approach enables the cell to harvest a broader spectrum of sunlight than either material could alone.

Theoretically, these tandem cells could reach 43% efficiency, meaning LONGi’s current achievement still has significant headroom for improvement.

A Competitive Landscape

While LONGi’s 35.5% claim is impressive for commercially scalable technology, it is not the highest efficiency ever recorded. The U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) developed a solar cell with 39.5% efficiency back in 2022, though that device used more exotic materials and fabrication processes not yet suited for mass production.

At the other end of the spectrum, specialized solar cells used in satellite and space applications can reach conversion efficiencies of 50%, but their astronomical cost and complex manufacturing make them impractical for terrestrial deployment.

What This Means for Clean Energy

The significance of LONGi’s achievement lies not in who holds the absolute record, but in the pathway to mass production it represents. Crystalline silicon-perovskite tandem cells can be manufactured using techniques compatible with existing silicon solar fabrication lines, potentially lowering the barriers to commercialization.

If LONGi or its competitors can bring 35%+ efficient panels to market at competitive prices, the implications for renewable energy deployment would be substantial:

Higher energy yield per square meter — critical for rooftop installations and land-constrained sites
Lower balance-of-system costs — fewer panels needed per installation reduces mounting hardware, wiring, and labor
Improved economics for solar farms — greater electricity output per acre improves project returns

The Road Ahead

LONGi believes crystalline silicon-perovskite tandem technology represents the future of solar energy. With a clear trajectory from 33.9% to 35.5% in under three years, the company is demonstrating steady progress toward the technology’s theoretical ceiling.

The broader solar industry is watching closely. As tandem cells transition from laboratory breakthroughs to commercial products, the next few years could see solar panel efficiencies that were considered science fiction just a decade ago — bringing the world closer to a genuinely sustainable energy future.

Sources:

https://www.engadget.com/2218081/chinese-solar-cell-efficiency-35-5-percent/

Photo by andreas160578 on Pixabay

Perovskite on Know the Tech

LONGi Shatters Solar Efficiency Record with 35.5% Perovskite-Silicon Tandem Cell

How Perovskite-Silicon Tandem Cells Work

A Competitive Landscape

What This Means for Clean Energy

The Road Ahead