Realization of High Mobility Synaptic Transistor through Control of Cross-Linking Agent in a Polymer Dielectric Layer for Emerging Electric Double Layer

The development of high-mobility neuromorphic transistors is essential to increase signal transmission speed and solve the von Neumann bottleneck issue. Herein, this work proposes cross-linked Poly(4-vinylphenol) (c-PVP) as a dielectric layer to form an electric double layer (EDL), which plays a key role in synaptic transistors, and measure the ratio-dependent characteristics of cross-linking agents in c-PVP. When the ratio of PVP to poly(melamine-co-formaldehyde) methylated (PMF) is 10:1, neuromorphic transistors is found to show the best performance with a memory window of 2.2 V and a mobility of 93.4 cm² V⁻¹ s⁻¹. Fourier-transform infrared spectroscopy (FT-IR) results show that the reduction in the concentration of the cross-linking agent generates more hydroxyl groups within the c-PVP film. The 10:1 c-PVP-based synaptic device has an ultra-low energy consumption of 15.8 pJ for a single pulse and a maximum paired pulse facilitation (PPF) index value of 291%. Additionally, synaptic characteristics, such as pulse duration time dependent plasticity, pulse intensity dependent plasticity, pulse rate dependent plasticity (SRDP), high band filtering, and short-term memory (STM) conversion to long-term memory (LTM), are also described and discussed. These results suggest that c-PVP/ZnON-based neuromorphic devices can be promising artificial synapses for memory and learning capabilities.