Over 12% Efficiency Nonfullerene All-Small-Molecule Organic Solar Cells with Sequentially Evolved Multilength Scale...

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Nonfullerene-based small-molecule organic solar cells (NFSM-OSCs) are promising for next-generation photovoltaics.
• Achieving high power conversion efficiency (PCE) requires precise control over molecular morphology and charge dynamics.

Purpose of the Study:

• To incorporate two near-infrared absorbing molecules into NFSM-OSCs.
• To achieve a record high PCE by optimizing blend morphology and charge transport.

Main Methods:

• Utilized a combined solvent additive and solvent vapor annealing approach.
• Tuned the crystalline morphology of ZnP-TBO and 6TIC blend.
• Investigated charge delocalization to reduce nongeminate recombination.

Main Results:

• Achieved a power conversion efficiency (PCE) of 12.08%.
• Improved crystallinity and formed multilength scale morphology.
• Enhanced charge mobility, charge extraction, fill factor, and short-circuit current density (Jsc).
• Reduced nongeminate recombination through effective charge delocalization.

Conclusions:

• The developed NFSM-OSCs represent a significant advancement in small-molecule organic solar cell technology.
• The combined annealing strategy effectively optimizes morphology for high performance.
• This work sets a new benchmark for PCE in small-molecule binary solar cells.