Ionogel-gated organic transistors and artificial synapses based on a composite of tosylate-doped poly(3,4-ethylenedioxythiophene) and insulating polyvinylpyrrolidone

• Published in: Macromolecular research 2023, 31(11), , pp.1095-1104
• Main Authors: So, Jaehee, Kim, Taemin, Shin, Jaehwan, Kim, Donguk, Kim, Felix Sunjoo
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemical properties; Chemical synthesis; Chemistry; Chemistry and Materials Science; Circuit components; Complex Fluids and Microfluidics; Conducting polymers; Current modulation; Electric properties; Electrical conductivity; Electrical resistivity; Electrolytes; Hysteresis; Nanochemistry; Nanotechnology; Nonaqueous electrolytes; Physical Chemistry; Polymer matrix composites; Polymer Sciences; Polymers; Polyvinylpyrrolidone; Povidone; Resveratrol; Soft and Granular Matter; Synapses; Toluene; Transconductance; Transistors; Transport properties; 고분자공학
• ISSN: 1598-5032; 2092-7673
• DOI: 10.1007/s13233-023-00188-9

Both ionic and electronic conductions in a channel are important factors to determine device characteristics of organic electrolyte-gated transistors (OEGTs) and artificial synaptic devices. Herein, synthesis and characterization of conducting polymer composites, based on poly(3,4-ethylenedioxythiophene) (PEDOT) doped with p-toluene sulfonate (Tos) counterions and insulating polyvinylpyrrolidone (PVP), are reported. The PEDOT:PVP ratio in the composite is easily tuned by varying the composition of the precursor solution. The PEDOT:Tos/PVP composites exhibit a higher electrical conductivity than pristine PEDOT:Tos. Ionogel-gated transistors based on the composites show good current modulation in a depletion mode. The transistors with 40% PVP by polymer weight show higher transconductance and larger hysteresis strength. Spectroscopic and electrochemical measurements reveal that addition of PVP affects the capability of doping-state modulation and the kinetics of ion conduction. With these properties, the PEDOT:Tos/PVP composite-based OEGTs exhibit good synaptic characteristics with reliable multi-level inhibitory and excitatory operations, suggesting the effectiveness of the strategy of introducing an electrically insulating polymer in conducting polymer composites to tune their charge-transport properties and device characteristics. Graphical abstract Conducting polymer composites of PEDOT:Tos/PVP are synthesized and used as a channel layer of organic electrolyte-gated transistors (OEGTs) and artificial synaptic devices. The devices with 40% PVP by polymer weight show a high transconductance and a large hysteresis strength, enabling good synaptic characteristics with reliable multi-level operations.