Air-Stable Perylene Diimide Trimer Material for N-Type Organic Electrochemical Transistors

Area of Science:

• Materials Science
• Organic Electronics
• Electrochemistry

Background:

• Organic electrochemical transistors (OECTs) require stable active materials with efficient ionic and electronic transport.
• Developing air-stable n-type organic mixed ionic-electronic conductors (OMIECs) is crucial for advancing OECT technology.

Purpose of the Study:

• To report a novel method for creating air-stable n-type OMIEC films using a solution-processable small molecule.
• To investigate the impact of side chain removal on film properties and OECT performance.

Main Methods:

• Synthesis of a helical perylene diimide trimer with cleavable alkyl side chains (hPDI[3]-C11).
• Film formation via solution processing followed by thermal annealing to remove side chains, yielding hPDI[3]-H.
• Fabrication and characterization of OECTs using hPDI[3]-H as the active layer.

Main Results:

• The hPDI[3]-H films exhibited reduced hydrophobicity, increased ordering, and a deeper LUMO level after side chain removal.
• Achieved OECTs demonstrated high transconductance (44 mS), volumetric capacitance (≈250 F cm-3), and excellent stability (> 5 weeks).
• Demonstrated practical applications including a glucose sensor and an electrochemical inverter.

Conclusions:

• Side chain cleavage post-film formation is an effective strategy for producing stable, high-performance n-type OMIEC films.
• This approach enables the development of a wider range of molecular semiconductors for stable OECTs.
• The developed hPDI[3]-H material shows significant promise for various electronic and sensing applications.