Selectively Modulating Componential Morphologies of Bulk Heterojunction Organic Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Renewable Energy

Background:

• Controlling nanoscale morphology in bulk heterojunction films is crucial for organic solar cells (OSCs) but challenging with conventional post-treatments.
• Existing methods often require harsh conditions, limiting substrate choices and device stability.

Purpose of the Study:

• To develop a mild processing strategy for high-performance organic solar cells.
• To achieve precise control over the nanoscale morphology of bulk heterojunction films.
• To demonstrate the fabrication of flexible organic solar cells using sustainable materials.

Main Methods:

• Development of a near-infrared photon-assisted annealing (NPA) strategy combining top NIR light illumination and bottom heating.
• Selective tuning of molecular arrangement and assembly of narrow bandgap acceptors.
• Fabrication of organic solar cells on thermolabile polyethylene terephthalate substrates.

Main Results:

• Achieved optimal film morphologies and an acceptor-rich top surface in the active layer.
• Obtained a remarkable power conversion efficiency (PCE) of 19.25% for binary organic solar cells.
• Demonstrated excellent mechanical stability in top-illuminated flexible OSCs.

Conclusions:

• The NPA strategy offers a mild and effective method for fabricating high-performance organic solar cells.
• This approach enables the use of diverse and even recycled substrates for flexible solar cell applications.
• The developed technique holds significant potential for advancing sustainable organic solar cell technology.