11-bit two-dimensional floating-gate memories.

Wang, Yanrong; Cai, Yuchen; Wang, Feng; Yan, Tao; Li, Shuhui; Cao, Mingyang; Hong, Ruohao; Zhai, Baoxing et al. · Nat Commun · 2025

basic_science · Level V

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Abstract

Floating-gate memories (FGMs) show great promise for neuromorphic computing in efficient data-centric applications. However, their limited single-device state capacity remains insufficient for highly integrated precision computing. Here, we demonstrate 11-bit two-dimensional (2D) MoS<sub>2</sub> FGMs by contacting the 2D channels with bismuth electrodes, enabling 100 μA on-state current with 10<sup>8</sup> on/off ratio and reducing the current noise by 3 times (approaching the equipment limits) due to the Schottky barrier-free interfaces. Moreover, we employed a dual-pulse state editing scheme enhancing the stability of our FGMs. The devices show as high as 2,249 distinct conductance levels (>11-bit) while maintaining 230 ns operation speed, >10<sup>4 </sup>s retention, and >10<sup>5</sup> cycle endurance. Furthermore, the gate-injection operation prevents the influence from generated defects during cycling, maintaining low noise even after 10<sup>5</sup> cycles and at 85 °C. Theoretical analysis reveals interfacial defects as the primary state-number limitation, suggesting 17-bit capacity is achievable through further trap density reduction. This work establishes 2D FGMs as promising candidates for high-bit-density, low-power neuromorphic hardware.