Research and Development Center for Smart Textile Technology and Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei 106, Taiwan.
Department of Chemical Engineering, National Taiwan University, Taipei 106, Taiwan.
ACS Appl Mater Interfaces. 2020 Jul 29;12(30):33968-33978. doi: 10.1021/acsami.0c06109. Epub 2020 Jul 14.
Brain-inspired synaptic transistors have been considered as a promising device for next-generation electronics. To mimic the behavior of a biological synapse, both data processing and nonvolatile memory capability are simultaneously required for a single electronic device. In this work, a simple approach to realize a synaptic transistor with improved memory characteristics is demonstrated by doping an ionic additive, tetrabutylammonium perchlorate (TBAP), into an active polymer semiconductor without using any extra charge storage layer. TBAP doping is first revealed to improve the memory window of a derived transistor memory device from 19 to 32 V (∼68% enhancement) with an on/off current ratio over 10 at = -10 V. Through morphological analysis and theoretical calculations, it is revealed that the association of anion with polymers enhances the charge retention capability of the polymer and facilitates the interchain interactions to result in improved memory characteristics. More critically, the doped device is shown to successfully mimic the synaptic behaviors, such as paired-pulse facilitation (PPF), excitatory and inhibitory postsynaptic currents, and spike-rate dependent plasticity. Notably, the TBAP-doped device is shown to deliver a PPF index of up to 204% in contrast to the negligible value of an undoped device. This study describes a novel approach to prepare a synaptic transistor by doping conjugated polymers, which can promote the future development of artificial neuromorphic systems.
受生物突触启发的突触晶体管被认为是下一代电子学中很有前途的一种器件。为了模拟生物突触的行为，单个电子设备需要同时具备数据处理和非易失性存储功能。在这项工作中，通过在活性聚合物半导体中掺杂离子添加剂四丁基高氯酸铵（TBAP），而不使用任何额外的电荷存储层，展示了一种简单的方法来实现具有改进的存储特性的突触晶体管。TBAP 掺杂首先被揭示可以改善衍生晶体管存储器件的存储窗口，使其从 19 V 提高到 32 V（提高约 68%），在 = -10 V 时的开/关电流比超过 10。通过形态分析和理论计算，揭示了阴离子与聚合物的缔合增强了聚合物的电荷保持能力，并促进了链间相互作用，从而改善了存储特性。更重要的是，所掺杂的器件成功模拟了突触行为，如成对脉冲易化（PPF）、兴奋性和抑制性突触后电流以及尖峰率依赖性可塑性。值得注意的是，与未掺杂器件的可忽略的 PPF 指数相比，掺杂 TBAP 的器件的 PPF 指数高达 204%。这项研究描述了一种通过掺杂共轭聚合物来制备突触晶体管的新方法，这将有助于推动人工神经形态系统的未来发展。
