Tuning the Morphology of Solution-Sheared P3HT:PCBM Films

Area of Science:

• Materials Science
• Organic Electronics
• Renewable Energy

Background:

• Organic bulk heterojunction (BHJ) solar cells offer a sustainable energy solution.
• Current research often relies on spin coating, limiting scalability for consumer applications.
• High-throughput printing techniques are essential for commercializing flexible and semitransparent electronics.

Purpose of the Study:

• Investigate solution-sheared film morphology for BHJ solar cells.
• Understand the impact of processing parameters on P3HT:PCBM blends.
• Explore scalable fabrication methods beyond spin coating.

Main Methods:

• Solution shearing technique for film deposition.
• Grazing incident X-ray scattering (GISAXS and GIWAXS) for structural analysis.
• UV-vis spectroscopy for optical characterization.

Main Results:

• Solution shearing allows control over P3HT aggregation, conjugation length, and PCBM domain size.
• Substrate chemistry influences P3HT molecular orientation, unlike spin-coated films.
• PSS substrates promote a favorable face-on orientation for enhanced solar cell performance.

Conclusions:

• Solution shearing is a viable, scalable technique for fabricating high-performance BHJ solar cells.
• Controlling film morphology through substrate chemistry is key for optimizing device efficiency.
• This work paves the way for cost-effective, large-area production of organic solar cells.