SolarLayer Perovskite-Silicon Tandem Solar Cell Pilot Line Completes Validation: Efficiency Surpasses 32 Percent

SolarLayer Perovskite-Silicon Tandem Solar Cell Pilot Line Completes Validation: Efficiency Surpasses 32 Percent

SolarLayer, a perovskite-silicon tandem solar-cell mass-production process jointly developed by CATL and LONGi Green Energy, has completed pilot-line validation with an average production efficiency of 32.4 percent — significantly above mainstream PERC cells at 24.5 percent and TOPCon cells at 26.1 percent.

The key innovation of SolarLayer is its compatibility with existing PERC lines. The tandem cell uses conventional P-type monocrystalline silicon as the bottom cell and a wide-bandgap perovskite as the top cell, with electrical connection through a transparent conductive adhesive. That design lets manufacturers upgrade to tandem technology by adding only a small amount of equipment to existing PERC lines; the retrofit investment is just 40 percent of building a new TOPCon line.

Li Hongliang, president of CATL's solar business, said the company will deploy SolarLayer production lines first at its facilities in Ningde, Fujian, and Xining, Qinghai, reaching 1.2 GW of mass-production capacity in the second half of 2026. The long-term goal is to upgrade the global PERC installed base to tandem technology, with a potential retrofit scale of 380 GW.

SolarLayer cells passed 1,000 hours of accelerated aging at 85 degrees Celsius and 85 percent humidity with efficiency degradation under 4 percent — markedly better than pure perovskite cells. This durability result clears the central commercial hurdle for perovskite technology.