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 3 at V G = −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.

Interfaces showed great influence on polymer alignment, charge transport and meta-stable molecular packing for solution sheared devices.

Developing reliable memory devices with stable information storage capability in water is important for environmental and healthcare applications. However, it is challenging because water easily causes current leakage and information loss in conventional memory devices. This article reports a transistor-based graphene memory for which writing/erasing is through controlling the nanometer-thin water layer between graphene and its silica support. Using an interfacial water layer with a tunable thickness to switch the graphene electron-trapping extent allows the device to function in water, which is completely different from any current memory mechanisms. Stable high- and low-conductance (ON and OFF) states can be achieved by applying positive and negative gate voltages to control the water layer thickness as the writing/erasing processes, which is supported by our atomic force microscopy and Raman spectroscopy experimental results and theoretical predictions. The high stability in water and reversible switching property based on the nanometer-thin insulating water layer could facilitate the realization of ultra-compact 2D nonvolatile memories for various underwater applications.