Abstract
2D ultrathin oxides derived from liquid metals represent a unique class of 2D materials, offering low-temperature, scalable, and ambient-processable alternatives to conventional synthesis methods. Here, 2D ultrathin indium oxide (InO_X) memtransistors are fabricated via a reproducible liquid-metal-printing process at 200℃ in ambient air, combining touch printing and blade coating. The resulting InO_X films exhibit nanoscale thickness (~4 nm), a wide optical bandgap (~3.7 eV), and a polycrystalline, oxygen-deficient structure. Their intrinsically high conductivity is converted into stable semiconducting behavior through dry-air annealing. The fabricated memtransistors display robust, gate-tunable bipolar memristive switching with excellent endurance over 500 cycles and strong device-to-device uniformity. Notably, they achieve high switching ratios up to 10~(3.63), outperforming most previously reported 2D memtransistors synthesized under high-temperature or vacuum conditions. The memristive behavior is governed by space-charge-limited conduction extending to the trap-filled limit, driven by carrier trapping/detrapping within exponentially distributed trap states. Moreover, the devices emulate synaptic plasticity and neuromodulation, achieving recognition accuracies up to 88.3% in artificial neural network simulations for handwritten image recognition. These results establish liquid-metal-printed ultrathin InO_X as a promising, scalable platform for next-generation 2D neuromorphic and memory device technologies.
NETL
NSTL
Wiley