Optimization of organic electrochemical transistors for sensor applications

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 49; no. 1; pp. 34 - 39
• Main Authors: Yaghmazadeh, Omid, Cicoira, Fabio, Bernards, Daniel A, Yang, Sang Y, Bonnassieux, Yvan, Malliaras, George G
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 2011; Wiley
• Subjects: Application fields; Applied sciences; Channels; chemical and biological sensors; computer modeling; conjugated polymers; device modeling; Electrodes; Electronics; Engineering Sciences; Exact sciences and technology; Gates; Mathematical models; Micro and nanotechnologies; Microelectronics; organic electrochemical transistors; Polymer industry, paints, wood; Reproduction; Semiconductor devices; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensors; Technology of polymers; Transistors; computer modeling; chemical and biological sensors; Aromatic polymer; Transistor; device modeling; Experimental study; Optimal design; Electrochemical detector; Conducting polymers; sensors; Thiophene derivative polymer; Styrenesulfonate polymer; Doped polymer; Numerical simulation; Manufacturing; Photolithography; organic electrochemical transistors; conjugated polymers
• ISSN: 0887-6266; 1099-0488; 1099-0488
• DOI: 10.1002/polb.22129

Despite the recent interest in organic electrochemical transistors (OECTs) as chemical and biological sensors, little is known about the role that device architecture and materials parameters play in determining sensor performance. We use numerical modeling to establish design rules in two regimes of operation: We find that for operation as an ion‐to‐electron converter, the response of OECTs is maximized through the use of a gate electrode that is much larger than the channel or through the use of a nonpolarizable gate electrode. Improving the conductivity of the polymer and using a channel geometry that maximizes channel width and thickness, and minimizes channel length helps increase the response. For operation as an electrochemical sensor, the sensitivity is maximized in OECTs with gate electrodes that are smaller than their channels. The sensitivity can be improved by increasing the charge carrier mobility and the capacitance per unit area of the conducting polymer, and also its ability to be penetrated by ions from the electrolyte. A channel geometry that maximizes channel width and minimizes channel length also improves sensitivity.