KIER Sets World Record for Perovskite/CIGS Tandem Solar Cell Efficiency

The Korea Institute of Energy Research (KIER) has achieved a world-record power conversion efficiency of 26.7% for perovskite/CIGS tandem solar cells. This breakthrough represents a significant leap in the performance of solar cells that combine perovskite with Copper Indium Gallium Selenide (CIGS) materials.

KIER successfully pushed the efficiency of this specific material combination to the 26.7% mark, establishing a new global benchmark for perovskite/CIGS tandems. The result demonstrates the potential for these hybrid structures to outperform traditional single-junction silicon cells by capturing more energy from the solar spectrum.

The Mechanics of Tandem Cells

Tandem solar cells operate by layering two different light-absorbing materials to capture a broader spectrum of sunlight than a single-junction cell can manage. In this specific configuration, the perovskite layer and the CIGS layer possess complementary absorption properties. While one material captures high-energy photons from the blue end of the spectrum, the other captures lower-energy photons from the red and infrared ends. This dual-layer approach reduces the energy lost as heat and increases the overall electrical output.

Industry Implications

Increasing the efficiency of tandem cells is critical for the broader economics of the renewable energy sector. By maximizing the power output per square meter of installation, higher efficiency directly reduces the balance-of-system costs—such as land, racking, and wiring—required to generate the same amount of electricity. As the industry seeks to accelerate the transition to renewable energy, these gains are essential for making solar power more competitive against fossil fuels, particularly in space-constrained environments where every inch of surface area must be optimized.

The Path Forward

While the 26.7% efficiency record proves the theoretical potential of the perovskite/CIGS pairing, the next phase of development must focus on long-term stability and scalability. Perovskites are known for their high performance but often struggle with degradation when exposed to moisture and heat over time. Future research will need to determine if this record-breaking efficiency can be maintained in commercial-scale modules under real-world outdoor conditions to ensure the technology is viable for mass deployment.