Dynamic Model of the Short-Term Synaptic Behaviors of PEDOT-based Organic Electrochemical Transistors with Modified Shockley Equations

Haonian Shu; Haowei Long; Haibin Sun; Baochen Li; Haomiao Zhang; Xiaoxue Wang

doi:10.1021/acsomega.1c06864

Dynamic Model of the Short-Term Synaptic Behaviors of PEDOT-based Organic Electrochemical Transistors with Modified Shockley Equations

ACS Omega. 2022 Apr 19;7(17):14622-14629. doi: 10.1021/acsomega.1c06864. eCollection 2022 May 3.

Authors

Haonian Shu¹, Haowei Long², Haibin Sun¹, Baochen Li¹, Haomiao Zhang³, Xiaoxue Wang¹

Affiliations

¹ Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 W. Woodruff Ave, Columbus, Ohio 43210, United States.
² School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China.
³ State Key Laboratory of Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China.

Abstract

Neuromorphic computing is an emerging area with prospects to break the energy efficiency bottleneck of artificial intelligence (AI). A crucial challenge for neuromorphic computing is understanding the working principles of artificial synaptic devices. As an emerging class of synaptic devices, organic electrochemical transistors (OECTs) have attracted significant interest due to ultralow voltage operation, analog conductance tuning, mechanical flexibility, and biocompatibility. However, little work has been focused on the first-principal modeling of the synaptic behaviors of OECTs. The simulation of OECT synaptic behaviors is of great importance to understanding the OECT working principles as neuromorphic devices and optimizing ultralow power consumption neuromorphic computing devices. Here, we develop a two-dimensional transient drift-diffusion model based on modified Shockley equations for poly(3,4-ethylenedioxythiophene) (PEDOT)-based OECTs. We reproduced the typical transistor characteristics of these OECTs including the unique non-monotonic transconductance-gate bias curve and frequency dependency of transconductance. Furthermore, typical synaptic phenomena, such as excitatory/inhibitory postsynaptic current (EPSC/IPSC), paired-pulse facilitation/depression (PPF/PPD), and short-term plasticity (STP), are also demonstrated. This work is crucial in guiding the experimental exploration of neuromorphic computing devices and has the potential to serve as a platform for future OECT device simulation based on a wide range of semiconducting materials.