Simultaneous Performance and Stability Improvement of a p-Type Organic Electrochemical Transistor through Additives

Abstract

Advancements in organic electrochemical transistor (OECT) applications have been largely driven by the development of organic electronic materials that allow for simultaneous ionic and electronic transport in the bulk of their films. These studies focus on achieving high steady-state OECT performance, governed by the electronic charge mobility and the capacitance of the polymer film in the channel, and an often underlooked property is the long-term operational stability. In this work, we present a strategy to improve the performance of p-type OECTs along with operational stability via two additives, i.e., a high-boiling-point solvent (chlorobenzene) and a Lewis acid (tris(pentafluoro phenyl)borane). Addition of a small amount of a cosolvent additive changes the arrangement of glycolated thiophene-based copolymer chains on the substrate toward a direction that allows for more efficient hole transport. The Lewis acid, on the other hand, boosts the OECT stability, mainly by preventing oxidative degradation. Using both additives in the solution grants OECTs with high operational stability and performance through changes in the film microstructure and the polymer's sensitivity to oxygen. This study highlights the use of additives as a means to enhance the OECT figure of merits without the need for new polymer synthesis.

Unravelling Disorder Effects on Thermoelectric Properties of Semicrystalline Polymers in a Wide Range of Doping Levels

“…[ 42 ] The appearance of small P P peaks at 0 V in Figure 2b might be ascribed to the mild penetration of external ions by sandwiching polymer layer and IL between two substrates for V G ‐dependent spectroscopy measurements (Figure S14, Supporting Information). [ 43,44 ]…”

“…[42] The appearance of small P P peaks at 0 V in Figure 2b might be ascribed to the mild penetration of external ions by sandwiching polymer layer and IL between two substrates for V G -dependent spectroscopy measurements (Figure S14, Supporting Information). [43,44] Table 1. HOMO, LUMO energy levels, threshold voltage (V TH ), maximum drain current (I D,max ), maximum electrical conductivity (σ max ), and power factor (S 2 σ max ) of PPDT2FBT-based polymers.…”

A guide for the characterization of organic electrochemical transistors and channel materials

“…Synthetic strategies have made longer chains with stiff backbones to improve charge transport and removed the contribution of ionic components in the film to enhance the electronic charge density. [26][27][28] Postprocessing efforts (such as side chains removal, 29 annealing, 30 acid post-treatment, 31 solvent mixtures 32,33 or small molecule additives in the solution 34,35 ) aimed to improve chain aggregation, 25 reduce traps, 36 increase the charge carrier density or introduce chemically doped charges in the film. 37 All these efforts have focused on OECT amplification performance.…”

Molecularly Hybridized Conduction in DPP‐Based Donor–Acceptor Copolymers toward High‐Performance Iono‐Electronics

“…[ 25 ] The field has thus made substantial efforts to find alternative materials mainly employing sidechain engineering, [ 27 ] copolymerization, [ 20,28,29 ] and additive strategies. [ 30 ] A recent notable candidate is poly(2‐(3,3′‐bis(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)‐[2,2′‐bithiophen]‐5‐yl)thieno[3,2‐b]thiophene), pg2T‐TT, a p‐type mixed conductor which, despite a few remaining challenges around stability, has shown outstanding performance in electrochemical devices, synaptic transistors, and sensing devices. [ 9,26 ] Structurally, pg2T‐TT depicts a model conjugated backbone flanked with polar sidechains for facile ion uptake and conductance modulation; several derivatives have thus been reported by varying the side chains and their distribution.…”

“…[25] The field has thus made substantial efforts to find alternative materials mainly employing sidechain engineering, [27] copolymerization, [20,28,29] and additive strategies. [30] A recent notable candidate is poly (…”