Hybrid Interface Engineering With Piperidinium Ionic Polymers Toward 21% Efficiency of Organic Solar Cells

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• The cathode interlayer (CIL) is crucial for organic solar cell (OSC) performance, influencing conductivity and work function.
• Perylene-diimide-based CILs face limitations in conductivity and thickness tolerance, hindering widespread application.

Purpose of the Study:

• To develop a novel hybrid CIL strategy to overcome the limitations of existing perylene-diimide-based CILs.
• To enhance the performance and stability of organic solar cells through improved cathode interlayers.

Main Methods:

• Incorporation of a piperidinium ionic polymer (PIP) into PDINN to create a hybrid CIL.
• Investigating the effects of piperidinium ionization on film morphology, molecular packing, and interfacial properties.
• Fabricating and testing organic solar cells utilizing the novel hybrid CIL.

Main Results:

• The hybrid PDINN:PIP CIL demonstrated improved film formation, tighter molecular packing, and enhanced conductivity.
• Optimized cathode work function and superior thickness insensitivity were achieved.
• Organic solar cells with the hybrid CIL achieved a power conversion efficiency (PCE) of 20.85%, outperforming control devices (19.80%).

Conclusions:

• Piperidinium ionization in hybrid CILs effectively enhances OSC performance by improving interfacial properties and conductivity.
• The developed hybrid CIL strategy shows broad applicability across different active-layer systems.
• This research highlights a promising approach for advancing organic solar cell technology.