Decoding non-fullerene acceptors for organic solar cells: a theoretical structure-property-performance perspective

Area of Science:

• Materials Science
• Physical Chemistry
• Renewable Energy

Background:

• Organic solar cells (OSCs) are promising due to flexibility and light weight.
• Traditional fullerene acceptors limit OSC performance due to poor absorption and energy losses.
• Non-fullerene acceptors (NFAs) are emerging as advanced alternatives.

Purpose of the Study:

• To provide theoretical insights into the structure-property-performance relationships of NFAs.
• To analyze how molecular design influences electronic structure, optical behavior, and charge transport.
• To guide the development of high-efficiency NFAs for organic photovoltaics.

Main Methods:

• Utilized theoretical and computational methods including Density Functional Theory (DFT) and Machine Learning (ML).
• Calculated key descriptors: HOMO-LUMO levels, bandgap, reorganization energy, and exciton binding energy.
• Investigated molecular packing and intermolecular interactions.

Main Results:

• Rational molecular engineering (donor-acceptor architectures, end-group modification, etc.) tunes optoelectronic properties.
• State-of-the-art NFAs achieve power conversion efficiencies up to 20% with narrow bandgaps and strong NIR absorption.
• Morphology and intermolecular interactions are critical for charge transport and recombination dynamics.

Conclusions:

• Theoretical understanding combined with experimental data enables prediction and optimization of NFA performance.
• Future multiscale and data-driven modeling will accelerate the design of next-generation NFAs.
• NFAs are key to developing highly efficient, stable, and commercially viable organic solar cells.