Shu Haonian, Long Haowei, Sun Haibin, Li Baochen, Zhang Haomiao, Wang Xiaoxue
Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 W. Woodruff Ave, Columbus, Ohio 43210, United States.
School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, P. R. China.
ACS Omega. 2022 Apr 19;7(17):14622-14629. doi: 10.1021/acsomega.1c06864. eCollection 2022 May 3.
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.
神经形态计算是一个新兴领域，有望突破人工智能（AI）的能效瓶颈。神经形态计算面临的一个关键挑战是理解人工突触器件的工作原理。作为一类新兴的突触器件，有机电化学晶体管（OECT）因其超低压操作、模拟电导调谐、机械灵活性和生物相容性而引起了广泛关注。然而，很少有工作聚焦于OECT突触行为的第一性原理建模。对OECT突触行为进行模拟对于理解作为神经形态器件的OECT工作原理以及优化超低功耗神经形态计算器件至关重要。在此，我们基于修正的肖克利方程为基于聚（3,4-乙撑二氧噻吩）（PEDOT）的OECT开发了一个二维瞬态漂移扩散模型。我们重现了这些OECT的典型晶体管特性，包括独特的非单调跨导-栅极偏置曲线和跨导的频率依赖性。此外，还展示了典型的突触现象，如兴奋性/抑制性突触后电流（EPSC/IPSC）、双脉冲易化/抑制（PPF/PPD）和短期可塑性（STP）。这项工作对于指导神经形态计算器件的实验探索至关重要，并且有潜力作为基于广泛半导体材料的未来OECT器件模拟的平台。
