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

Nguyen-Dang, Tung; Bao, Si Tong; Kaiyasuan, Chokchai; Li, Kunyu; Chae, Sangmin; Yi, Ahra; Joy, Syed; Harrison, Kelsey et al. · Adv Mater · 2024

basic_science · Level V

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Abstract

A new method is reported to make air-stable n-type organic mixed ionic-electronic conductor (OMIEC) films for organic electrochemical transistors (OECTs) using a solution-processable small molecule helical perylene diimide trimer, hPDI[3]-C<sub>11</sub>. Alkyl side chains are attached to the conjugated core for processability and film making, which are then cleaved via thermal annealing. After the sidechains are removed, the hPDI[3] film becomes less hydrophobic, more ordered, and has a deeper lowest unoccupied molecular orbital (LUMO). These features provide improved ionic transport, greater electronic mobility, and increased stability in air and in aqueous solution. Subsequently, hPDI[3]-H is used as the active material in OECTs and a device with a transconductance of 44 mS, volumetric capacitance of ≈250 F cm<sup>-3</sup>, µC<sup>*</sup> value of 1 F cm<sup>-1</sup> V<sup>-1</sup> s<sup>-1</sup>, and excellent stability (> 5 weeks) is demonstrated. As proof of their practical applications, a hPDI[3]-H-based OECTs as a glucose sensor and electrochemical inverter is utilized. The approach of side chain removal after film formation charts a path to a wide range of molecular semiconductors to be used as stable, mixed ionic-electronic conductors.