CEA researchers at INES report 21.2% efficiency for a flexible perovskite solar cell with an active area of 0.28 cm²
The team reduced energy losses through an anti-reflective coating and changes to the electrical connections to attain this new level over the previous internal record of 19.1%
Further work will focus on optimizing the cell layers and developing flexible substrates with greater resistance to heat, deformation and radiation
Researchers from CEA at France’s National Solar Energy Institute (INES) have achieved a new internal conversion efficiency of 21.2% for flexible perovskite solar cells on a polyethylene terephthalate (PET) substrate. The result, achieved on an active area of 0.28 cm², improves the team’s previous internal record of 19.2%
According to INES, the researchers incorporated an anti-reflective coating and redesigned the electrical connections to reduce energy losses. The efficiency increase is 2 percentage points, or about 10.4% relative to the previous result.
Benchmarking its result against a world-record efficiency of 24.52% on an active area of 0.092 cm², CEA says its device has an active area of 0.28 cm², about 3 times larger, but its efficiency falls short by 3.32 percentage points.
Flexible plastic substrates cannot withstand high processing temperatures. Cells must therefore be made at lower temperatures, which can cause defects and reduce efficiency compared with cells made on glass, according to INES. Researchers are developing low-temperature processes, protective treatments and printing methods to improve performance and durability.
The CEA team plans to optimize the cell layers further and test conductive materials as next steps to improve current extraction and resistance to environmental conditions. It will also explore flexible substrates that better withstand heat, bending and radiation.
These lightweight cells could be used in smart textiles, buildings and space systems. The research forms part of the European JUMP INTO SPACE project, which includes developing a single-junction perovskite cell architecture on a flexible substrate.
CEA–INES reported 19.18% efficiency for flexible perovskite cells in 2021 under the EU-backed Apolo project (see 19.18% Power Conversion Efficiency For Flexible Perovskite).
