[Energy]+[Breakthrough]: Perovskite-Silicon Heterojunction Tandem Solar Cell Efficiency Breaks 37.5% World Record

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The ultimate pursuit of the photovoltaic industry is maximizing photovoltaic conversion efficiency at reasonable cost. In May 2030, Chinese PV leader LONGi Green Energy announced that its R&D team had achieved 37.5% efficiency in perovskite-silicon heterojunction tandem solar cells under laboratory conditions, independently certified by Germany's Fraunhofer Institute for Solar Energy Systems.

This figure breaks LONGi's own record of 36.2% set in October 2029 and far exceeds the 26.81% theoretical limit of monocrystalline silicon cells. Tandem cells stack absorber layers with different bandgaps to capture photons of different wavelengths from the solar spectrum, thereby breaking through the efficiency ceiling of a single material.

LONGi Central Research Institute President Li Zhenguo said: "37.5% is a milestone, but not the finish line. Our technology roadmap shows that the efficiency limit for perovskite-silicon tandem cells is around 43%. There is still considerable room for improvement toward the theoretical limit."

The key technical breakthrough lies in improved perovskite layer stability. LONGi's team adopted a novel two-dimensional/three-dimensional hybrid perovskite structure, extending the perovskite layer's lifespan from 500 hours to 3,000 hours in accelerated aging tests at 85 degrees Celsius and 85% relative humidity. This metric is approaching the 25-year service life requirement for PV modules.

However, a vast gap remains between laboratory and mass production. LONGi indicated that a pilot line for perovskite-silicon tandem cells will begin production in Q1 2031, with a mass production efficiency target of 33%. Core challenges for large-scale manufacturing include uniform large-area coating of the perovskite layer, environmental compliance for lead content, and reliability of encapsulation processes.

Bloomberg NEF solar analyst Jenny Chase commented: "LONGi's tandem cell progress is impressive, but the PV industry's history tells us that a 5-to-8-percentage-point gap often exists between laboratory and mass production efficiency. Converting 37.5% laboratory efficiency to mass production will likely take 3 to 5 years."