Advanced Strategy for High-Performance A-D-A'-D-A Type Non-Fused Ring Electron Acceptors with Nitrogen Heterocyclic...

Area of Science:

• Organic Electronics
• Materials Science
• Photovoltaics

Background:

• Nonfused ring electron acceptors (NFREAs) are cost-effective alternatives to traditional acceptors.
• Current NFREAs, often A-D-A structured with benzene cores, have limited tunability.
• Power conversion efficiencies (PCE) of NFREAs have surpassed 19%.

Purpose of the Study:

• To design novel NFREAs with enhanced tunability and photovoltaic performance.
• To explore the impact of nitrogen heterocyclic cores on NFREA properties.
• To overcome the limitations of benzene-based cores in NFREA design.

Main Methods:

• Design and synthesis of three A-D-A'-D-A structured NFREAs (TT, TYT, TTVP) with nitrogen heterocyclic cores.
• Theoretical calculations to evaluate electronic properties, including energy levels, absorption, and electron mobility.
• Comparison of designed NFREAs with a high-performance reference (TBT-26).

Main Results:

• The nitrogen heterocyclic cores enable precise tuning of energy levels and enhance molecular rigidity.
• TT and TTVP showed higher electron affinity, absorption intensity, and electron mobility than TBT-26.
• TTVP exhibited the highest electron affinity, narrowest bandgap (1.76 eV), and superior electron mobility (4.43 × 10⁻⁴ cm² V⁻¹ s⁻¹).

Conclusions:

• Nitrogen heterocyclic cores are effective in diversifying NFREA design.
• These novel NFREAs demonstrate potential for next-generation high-performance organic solar cells.
• The TTVP molecule represents a significant advancement in NFREA development.