Thickness-Insensitive Cathode Interlayer via Molecular-Scale Distance Regulation for Efficient Organic Solar Cells.

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Cathode interlayers (CILs) are crucial for organic solar cell (OSC) performance.
• Developing thickness-insensitive CIL materials (CIMs) for large-scale printing is a significant challenge.

Purpose of the Study:

• To design efficient CIMs by regulating molecular-scale distances.
• To achieve thickness-insensitive CIMs for printable OSCs.

Main Methods:

• Synthesized three CIMs (P3, P6, P9) with varying spacer lengths linking pyrene diimide (PyDI) units.
• Investigated the effect of spacer length on π-π stacking, doping, and conductivity.
• Evaluated OSC performance, thickness tolerance, and scalability.

Main Results:

• P6 exhibited optimal π-π stacking, efficient Br- doping, and enhanced conductivity.
• P6-based OSCs achieved high power conversion efficiencies (PCEs) of 19.90% (binary) and 20.04% (ternary).
• P6 demonstrated excellent batch consistency, thickness tolerance (retaining 80% PCE at 133 nm), and scalability.

Conclusions:

• A molecular-scale distance regulation strategy effectively designs high-performance, thickness-insensitive CIMs.
• The developed CIMs are suitable for industrial-scale production of efficient OSCs.
• This approach advances the development of printable and scalable organic solar cell technology.