Revealing the Full Potential of Glycolated Mixed Ionic-Electronic Semiconductors – Symmetric Monomer Polymerization to Boost Electrochemical Transistor Performance

TL;DR

This paper explores how polymer synthesis methods affect the performance of organic electrochemical transistors.

Contribution

A symmetric monomer polymerization method is introduced to eliminate homocoupling, improving transistor performance.

Findings

A homocoupling-free polymer shows a 3-fold increase in electronic mobility.

Symmetric polymerization leads to better bulk properties and OECT performance.

Homocoupling significantly impacts the performance of OECT channel materials.

Abstract

Organic electrochemical
transistors (OECTs) enable the transduction
of ionic signals into electronic outputs, positioning them as ideal
candidates for next-generation sensing and (bio)­signal processing
applications. Recent years have witnessed the development of various
OECT channel materials, affording insights into structural fine-tuning
to achieve optimal performance and/or stability. However, homocouplings,
commonly present in alternating conjugated polymers, have largely
been overlooked. This study investigates the effect of homocoupling
on OECT materials by employing two synthesis methods – standard
Stille polymerization and an alternative symmetric approach –
to create the p-type enhancement-mode benchmark polymer pgBTTT. The
impact of homocoupling, and its absence, is studied by comparing the
bulk properties of the two polymers and evaluating their respective
OECT metrics. The new, homocoupling-free polymer exhibits a notably
improved OECT performance (μC*), mainly due
to an average 3-fold increase in electronic mobility (μ).

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