Fig. 1: Comparison of characteristics among an array of 2D MoS2 NEMS resonators with varying diameters from 2 μm to 5 μm, with either uniform or nonuniform membrane profiles.
a AFM color maps of the array of resonators. The thin region shown by the black dashed line “A” has a thickness of 5.5 nm (Fig. S2d), and the thick region shown by the black dashed line “B” has a thickness of 19 nm (Fig. S2e). Inset: optical image. The zoomed-in AFM color maps of representative resonators with diameters of (b–d) 5 μm, (e) 4 μm, (f) 3 μm, and (g) 2 μm. Resonance measurements of Device “1–1” with wrinkles on the surface and with a diameter of 5 μm, including (h) mapping of the fundamental flexural mode shape, (i) resonances at varying VGS and a fixed vRF of 10 mV with the amplitude shown in a color scale, and (j) resonances at varying vRF with a fixed VGS of 10 V. In the resonator named “m–n”, m indicates the row number and n indicates the column in the array. Measurements of Device “5–1” with fewer wrinkles on the surface and with a diameter of 5 μm, including (k) mapping of the fundamental flexural mode shape, (l) resonances at varying VGS and a fixed vRF of 10 mV, with the amplitude shown in a color scale, and (m) resonances at varying vRF with a fixed VGS of 10 V. Raman mapping of the resonator array with the color showing the Raman peak amplitude for the (n) E2g1 peak and (o) A1g peak. Raman spectra of Devices (p) 1–1 and (q) 5–1 measured near the center of the suspended membrane. r Summarized Q factors of the resonator array and modeled Q factor vs. diameter relationship, with diameters ranging from 2 μm to 5 μm. We plot the highest Q factor for each device when varying the gate voltage. The red triangles are the Q factors for devices in the plate regime (thickness >10 nm) and the blue dots are the Q factors for devices in the membrane regime (thickness ≤10 nm)
