Improving Perovskite/CIGS Tandem Solar Cells for Higher Power Conversion Efficiency through Light Management and...

Area of Science:

• Materials Science
• Renewable Energy
• Photovoltaics

Background:

• Perovskite and chalcopyrite are leading absorbers for efficient all-thin-film tandem solar cells.
• Previous records established the potential of these material combinations.

Purpose of the Study:

• To achieve a new world record power conversion efficiency for perovskite/chalcopyrite tandem solar cells.
• To demonstrate advancements in device architecture and material optimization.

Main Methods:

• Fabrication of all-thin-film tandem solar cells using perovskite and chalcopyrite absorbers.
• Certified current-voltage (IV) measurements under steady-state conditions.
• Analysis of device parameters including bandgap and optical properties.

Main Results:

• A certified world record power conversion efficiency of 24.6 ± 1.1% was achieved.
• Key IV parameters included a short-circuit current density of 19.3 mA/cm², an open-circuit voltage of 1.765 V, and a fill factor of 71.8%.
• Significant improvement in current density was observed compared to previous records.

Conclusions:

• The study successfully demonstrates a new benchmark in tandem solar cell efficiency.
• Lowering the bandgap of the bottom subcell and enhancing the optics of the top perovskite cell were critical for the improved performance.