[70]fullerene-based materials for organic solar cells.

Area of Science:

• Materials Science
• Organic Electronics
• Photovoltaics

Background:

• Fullerene derivatives are crucial as electron acceptors in organic solar cells.
• Optimizing fullerene acceptors is key to enhancing device performance and stability.
• Existing materials like phenyl-C61-butyric acid methyl ester ([60]PCBM) have limitations.

Purpose of the Study:

• To synthesize and characterize novel [70]fullerene derivatives: phenyl-C71-propionic acid propyl ester ([70]PCPP) and phenyl-C71-propionic acid butyl ester ([70]PCPB).
• To evaluate the photovoltaic performance of these new derivatives in bulk heterojunction organic solar cells.
• To compare their performance against conventional fullerene acceptors like phenyl-C71-butyric acid methyl ester ([70]PCBM).

Main Methods:

• Synthesis and characterization of [70]PCPP and [70]PCPB.
• Fabrication and testing of organic solar cells using MDMO-PPV and P3HT as donor polymers.
• Atomic Force Microscopy (AFM) for morphological analysis.
• Optical modeling for performance prediction.

Main Results:

• [70]PCPP and [70]PCPB outperformed [70]PCBM in solar cells with MDMO-PPV, attributed to better phase compatibility.
• Both novel derivatives showed high performance comparable to [70]PCBM when paired with P3HT.
• Optical modeling predicted a potential 10% increase in short-circuit current density with [70]fullerene derivatives over C60-based materials.

Conclusions:

• The novel [70]fullerene derivatives, [70]PCPP and [70]PCPB, show significant promise as electron acceptors.
• Their high solubility and improved compatibility with donor polymers enhance organic solar cell efficiency.
• These materials represent a viable advancement for efficient bulk heterojunction organic solar cells.