• Title: Monolithic 3D-Integrated All-Solid Ion-Gated Carbon Nanotube Transistors With Tunable Ionic Conductance for Multi-Timescale Reservoir Computing (link)

    In this study, we propose all-solid ion-gated transistors (sIGTs) with semiconducting carbon nanotube (CNT) channels that enable wide-range engineering of ionic dynamics while remaining fully compatible with scalable thin-film processing.

    By precisely tuning the ionic content and thickness of the solid ionogel down to the sub-micron regime, ionic time constants ranging from microseconds to milliseconds were achieved within an identical device geometry.

    Electrical impedance spectroscopy (EIS) and small-signal analysis were used to systematically reveal the relationship between ionic conductance and frequency-dependent device response, and uniform, reliable device characteristics were demonstrated at up to 4-inch wafer scale as well as on flexible substrates.

    At the system level, two CNT sIGT layers with distinct ionic dynamics were vertically integrated through monolithic 3D (M3D) stacking to realize a dual-timescale physical reservoir capable of classifying time-varying input signals using a single readout layer.

    This work demonstrates the potential of sIGTs as a scalable hardware platform for multi-timescale signal processing in neuromorphic computing.

    This research was supported by the National Research Foundation of Korea (NRF), the Korea Planning & Evaluation Institute of Industrial Technology (KEIT), the Ministry of Science and ICT (MSIT), and the Ministry of Trade, Industry and Energy (MOTIE).