Electrochemical Thin‐Film Transistors using Covalent Organic Framework Channel

Covalent organic framework (COF) thin films have been successfully prepared and utilized as a channel material in electrical double‐layer (EDL) electrochemical transistors. 4,4′‐azodianiline (Azo) and 1,3,5‐triformylphloroglucinol(Tp) precursors are introduced to prepare azo (NN) functionalized ß‐keto‐enamine COF (Tp‐Azo) thin films. The EDL transistor exhibits a switching ratio of 103 times, a low threshold voltage of 0.6 V, and a field‐effect mobility of 0.53 cm2 V−1 s−1. The dynamic behavior of the transistor under different input signals shows responses, which are very similar to the biological synaptic behavior, indicating that the COF devices can be used as artificial synapses. This report opens a new direction in covalent–organic framework development in iontronic applications. 4,4′‐azodianiline functionalized ß‐keto‐enamine covalent–organic framework (COF) thin films are prepared on glass substrates. The COF film is used as the channel material in electrochemical transistors, which operate following the electrical double layer formation at the COF and electrolyte interface. The functionality of the synaptic behavior is successfully demonstrated using the dynamic response of the devices.