14.4% Efficiency For Organic Solar Modules

• SCUT researchers claim to have achieved 14.4% efficiency for 'large area' organic solar modules with an area of 18 cm²
• They used non-fullerene acceptor and non-halogen solvent o-xylene to reach a maximum efficiency of over 16%
• They claim side-chain engineering is an effective strategy to have highly efficient large-area modules

The South China University of Technology (SCUT) has reported 14.4% power conversion efficiency for high performance organic solar modules with an area of 18 cm². Researchers argue that this proves side-chain engineering is an effective strategy to approach non-fullerene acceptors for non-halogen solvent-processed highly efficient 'large-area' modules.

Their research work has been published in the scientific journal Joule under the title Single-Component Non-halogen Solvent-Processed High-Performance Organic Solar Cell Module With Efficiency over 14%.

For the research work, the team used a non-fullerene acceptor DTY6 to apply in an organic solar cell module device which – when blended with donor PM6 and using non-halogen solvent o-xylene – showed a power conversion efficiency of more than 16%.

In contrast, the researchers witnessed Y6 based organic solar cells processed with o-xylene generating less than 11% efficiency.

"The detailed studies reveal that extremely large domains appear in the Y6-based blend film because of the excessive aggregation of Y6, which results in the lowly efficient hole transfer from Y6 to PM6 and enhanced non-radiative recombination," explain the researchers. "On the contrary, the DTY6-based film shows a more reasonable domain size, thus ensuring the efficient hole transfer from DTY6 to PM6 and low non-radiative recombination."

According to the team, organic solar cells are mostly fabricated using small-area devices from highly toxic organic solvents by spin-coating in an inert atmosphere but it doesn't work in mass production. Their side-chain engineering process, on the other hand, led to higher efficiency for small area organic solar cells and large area modules.

Back in November 2019, SCUT along with German researchers from FAU, ZAE and HI ERN reported 12.6% power conversion efficiency for organic PV modules (see 12.6% Conversion Efficiency For Organic PV Module).