Resolving Ternary Morphology for High-Performance Thickness-Insensitive Organic Solar Cells.

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• High-performance organic solar cells (OSCs) face challenges with active layer thickness tolerance.
• This limitation hinders large-scale printing and cost-effective module manufacturing.

Purpose of the Study:

• To develop efficient ternary organic solar cells with improved thickness tolerance.
• To elucidate the morphological origins of enhanced performance in thick-film OSCs.

Main Methods:

• Fabrication of ternary OSCs using PM6/Y6 blend films incorporating small-molecule donor BTR-Cl.
• Utilizing targeted deuteration of Y6 and BTR-Cl.
• Employing grazing-incidence small-angle neutron scattering (GISANS) to resolve blend film morphology.

Main Results:

• Achieved a photoconversion efficiency of 17.7% at an active layer thickness of 300 nm.
• Observed enhanced short-range aggregation of Y6 and BTR-Cl, improving inter-domain connectivity.
• Demonstrated enhanced carrier mobility and suppressed space charge accumulation.

Conclusions:

• Incorporating BTR-Cl significantly improves the thickness tolerance of OSCs.
• Amorphous nanomorphology plays a critical role in carrier transport connectivity and device performance.
• Targeted deuteration combined with GISANS is effective for analyzing multicomponent OSC active layers.