Fig. 2: Multilevel storage performance.
a The output curves of a 2,249-level MoS2 FGM. b The IDS-time curves of the device. VDS = 1 V. c The IDS-time curves of three selected regions (red dashed boxes in Fig. 2b). σ320, σ321, and σ322 denote the noises of level 320, 321, and 322, respectively. d, e Rapid programming and erase processes by the dual-pulse editing method. The waveforms of the dual-pulse are shown as the insets. The widths of the two pulses are fixed at 90 ns, with an interval of 50 ns. The amplitude of pulse1 is increasing, while the amplitude of pulse2 (|Vtune | ) is fixed at 3.5 V. The read voltage is 1 V. f long-term retention performance of several selected storage levels over a period of 104 s. g The endurance performance of the device by the dual-pulse editing method, where the amplitudes of the dual pulses are gradually increased after every 25,000 cycles, and the on-off ratio of the device also increases accordingly. The widths of the dual pulses are fixed at 50 µs, with an interval of 50 µs. The corresponding dual-pulse amplitudes for erasing and programming within the four sets of 25,000 cycles are as follows: 4.6 V, –2 V, and –5.6 V, 3 V; 4.8 V, –2 V, and –5.8 V, 3 V; 5 V, –2 V, and –6 V, 3 V; 6 V, –2 V, and –7 V, 3 V.
