MXene is a hot family of transition metal carbides or nitrides demonstrating promising potentials in the fields of batteries, supercapacitors, and memristive devices. One of MXenes, i.e., five-atoms-type MXene (Ti ₃ C ₂ ), has been reported to fabricate memristive devices and show resistive switching. However, MXene has another big group of three-atoms-type rather than five-atoms-type based on fundamental chemical structure. Besides, the group of three-atoms-type MXene is rarely investigated to fabricate memristive devices. Moreover, the effect of three-atoms-type Mxene (i.e., V ₂ C) on the performance of memristive devices and the physical mechanisms behind have not been explored. In this work, we constructed the lattice structure and compared the fundamental properties of V ₂ C with Ti ₃ C ₂ using the first-principles calculation. Moreover, the diffusion coefficient and the conductivity of Ag ⁺ in V ₂ C and Ti ₃ C ₂ have been checked by the density functional theory (DFT). It can be revealed that V ₂ C has a more stable atomic structure, a higher conductivity, and a superior diffusion coefficient of Ag ⁺ in V ₂ C. In addition, we fabricated memristive devices of the Ag/V ₂ C/W and Ag/Ti ₃ C ₂ /W based on the simulation results for comparison. Next, electrical characteristics of V ₂ C and Ti ₃ C ₂ of memristive devices were tested including the variation of device-to-device and cycle-to-cycle, the endurance, and the ratio of R _off /R _on . The experimental data indicate that the memristive devices with V ₂ C have achieved more stable resistive switching behaviors. The results of this work provide a useful guideline and methodology for exploring and determining various types of MXenes in advance of the experimental fabrication of memristive devices.

Yize Zhao

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