n-Type Organic Electrochemical Transistors with High Transconductance and Stability

Abstract

An n-type conjugated polymer based on diazaisoindigo (AIID) and fluorinated thiophene units is introduced. Combining the strong electron-accepting properties of AIID with backbone fluorination produced gAIID-2FT, leading to organic electrochemical transistors (OECTs) with normalized values of 4.09 F cm −1 V −1 s −1 and a normalized transconductance (g m,norm ) of 0.94 S cm −1 . The resulting OECTs exhibit exceptional operational stability and long shelf-life in ambient conditions, preserving 100% of the original maximum drain current after over 3 h of continuous operation and 28 days of storage in the air. Our work highlights the advantages of integrating strong electron acceptors with donor fluorination to boost the performance and stability of n-type OECTs.

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

“…As shown in Figure S7 in the Supporting Information, lgTNR demonstrated a linear dependence on the scan rate up to 200 mV s −1 , while bgTNR exhibited a linear dependence on the scan rate only up to 100 mV s −1 , suggesting relatively rapid charge/discharge cycling properties of lgTNR , which is in agreement with the shorter turn‐on and turn‐off times of lgTNR . [ 49,50 ]…”

“…As shown in Figure S7 in the Supporting Information, lgTNR demonstrated a linear dependence on the scan rate up to 200 mV s −1 , while bgTNR exhibited a linear dependence on the scan rate only up to 100 mV s −1 , suggesting relatively rapid charge/discharge cycling properties of lgTNR, which is in agreement with the shorter turn-on and turn-off times of lgTNR. [49,50] With suitably deep LUMO energy levels for facile charge injection and stable n-type transistor operation, we subsequently turned our attention to the spectroelectrochemical properties of thin films in aqueous electrolyte to mimic and evaluate the electrochemical process in an OECT. [51] Upon stepwise electrochemical reduction from 0.1 to −0.7 V, both lgTNR and bgTNR films show a significant bleaching of the two absorption bands in the visible region arising from the neutral species with concurrent gradual appearance of a broad absorption feature in the NIR region that can be attributed to the generation of negative polaronic species (Figure 3d,e).…”

Two‐Dimensional Conjugated Polymers: a New Choice For Organic Thin‐Film Transistors

“…In accordance with equation, the carrier transit time, one is compelled to consider the reduction of the channel length to enhance the response speed. [133] Currently, materials for the active layer in OECTs primarily include polypyrrole-based, [19,[134][135][136] polyaniline-based, [137][138][139] polythiophene-based, [18,[140][141][142][143][144][145] electron-deficient naphthalene diimide (NDI)-based, [145][146][147][148][149] isoindigo-based, [150][151][152][153] and lactonebased polymers. [154][155][156] However, the relationship between the most fundamental material properties and corresponding performance remains elusive because the microscopic structure and macroscopic fabrication of linear conjugated polymer thin films are still challenging to control.…”

Remaining useful life prediction towards cycling stability of organic electrochemical transistors

“…Up to now, OECTs with >10,000 cycle numbers and > 1 h cycle time, have been extensively reported [13][14][15][16][17][18]. For instance, by incorporating diazaisoin-digo and fluorinated thiophene units in an n-type OMIEC (gAIID-2FT), Wan et al, fabricated OECT with exceptional cycling stability (>3 h), which is attributed to the integrating strong electron acceptors with donor fluorination [19]. Moreover, by adopting a solid-state electrolyte, Wang et al introduced OECT for neuromorphic processing with excellent switching endurance (> 100,000,000 cycles) [20].…”