Low-Operating-Voltage Resistive Switching Memory Based on the Interlayer-Spacing Regulation of MoSe₂

The development of commercially available flexible and wearable devices requires low-operating-voltage circuit and resistive random access memory (RRAM). This paper reports the preparation and performances of low-operating-voltage RRAM based on the interlayer-spacing regulation of MoSe₂. Twine-jumble-like MoSe₂ clusters were synthesized via hydrothermal method. The average interlayer spacing in the clusters is higher than the value for bulk MoSe₂ by 9.969%. The layer count of the MoSe₂ sample predicted according to the experimental value of (Formula presented.) in the Raman spectroscopy is 1.403 while it is 2 regarding the characteristic of A_1g peak and the existence of B_2g peak, which is inconsistent with the results of scanning electron microscope and transmission electron microscope. Calculation of van der Waals force reveals that the twine-jumble-like MoSe₂ should not be considered as a bi-layer (or few-layer) crystal, but as a cluster consisting of a numerous monolayer crystals. Compared with the conventional nanosized MoSe₂, the SET/RESET voltages of the RRAM device based on the monolayer MoSe₂ clusters are decreased by 4–10 times while the switching ratio and endurance are increased by 2–40 and 2–10 times respectively, which is due to that the interstitial radius in the monolayer MoSe₂ clusters is higher than that of a silver ion.