Molecular Ordering Manipulation in Fused Oligomeric Mixed Conductors for High-Performance n-Type Organic Electrochemical Transistors.

Advanced n-type organic electrochemical transistors (OECTs) play an important part in bioelectronics, facilitating the booming of complementary circuits-based biosensors. This necessitates the utilization of both n-type and p-type organic mixed ionic-electronic conductors (OMIECs) exhibiting a balanced performance. However, the observed subpar electron charge transport ability in most n-type OMIECs presents a significant challenge to the overall functionality of the circuits.

Highly Efficient Mixed Conduction in a Fused Oligomer n-Type Organic Semiconductor Enabled by 3D Transport Pathways.

Tailoring organic semiconductors to facilitate mixed conduction of ionic and electronic charges when interfaced with an aqueous media has spurred many recent advances in organic bioelectronics. The field is still restricted, however, by very few n-type (electron-transporting) organic semiconductors with adequate performance metrics. Here, a new electron-deficient, fused polycyclic aromatic system, TNR, is reported with excellent n-type mixed conduction properties including a µC* figure-of-merit value exceeding 30 F cm V s for the best performing derivative.

Enhancing the Performance of N-Type Thermoelectric Devices via Tuning the Crystallinity of Small Molecule Semiconductors.

In the development of high-performance organic thermoelectric devices, n-type materials, especially with small molecule semiconductors, lags far behind p-type materials. In this paper, three small molecules are synthesized based on electron-deficient naphthalene bis-isatin building blocks bearing different alkyl chains with the terminal functionalized with 3-ethylrhodanine unit and studied their aggregation and doping mechanism in detail. It is found that crystallinity plays an essential role in tuning the doping behavior of small molecules.

Electron-Deficient Polycyclic Molecules via Ring Fusion for n-Type Organic Electrochemical Transistors.

The primary challenge for n-type small-molecule organic electrochemical transistors (OECTs) is to improve their electron mobilities and thus the key figure of merit μC*. Nevertheless, few reports in OECTs have specially proposed to address this issue. Herein, we report a 10-ring-fused polycyclic π-system consisting of the core of naphthalene bis-isatin dimer and the terminal moieties of rhodanine, which features intramolecular noncovalent interactions, high π-delocalization and strong electron-deficient characteristics.

Fluorinated Alcohol-Processed N-Type Organic Electrochemical Transistor with High Performance and Enhanced Stability.

Tuning the film morphology and aggregated structure is a vital means to improve the performance of the mixed ionic-electronic conductors in organic electrochemical transistors (OECTs). Herein, three fluorinated alcohols (FAs), including 2,2,2-trifluoroethanol (TFE), 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), and perfluoro--butanol (PFTB), were employed as the alternative solvents for engineering the n-type small-molecule active layer . Remarkedly, an impressive μ* of 5.

Efficient n-Type Small-Molecule Mixed Ion-Electron Conductors and Application in Hydrogen Peroxide Sensors.

Small-molecule semiconductors used as the channel of organic electrochemical transistors (OECTs) have been rarely reported despite their inherent advantages of well-defined molecular weight, convenient scale-up synthesis, and good performance reproducibility. Herein, three small molecules based on perylene diimides are readily prepared for n-type OECTs. The final molecules show preferred energy levels, tunable backbone conformation, and high film crystallinity, rendering them good n-type dopability, favorable volumetric capacities, and substantial electron mobilities.