Molecular Sieve-Assisted Inclined Growth of Ultrathin Nonlayered Cr2O3 Nanosheets for Reconfigurable Dual-Mode Memristive Switching.

Abstract

Two-dimensional materials show great potential as candidates for next-generation memristors. However, research on reconfigurable memristors essential to complex in-memory computing frameworks remains underexplored. Here, to tackle this challenge, a reliable vapor-phase growth method is developed to grow ultrathin nonlayered Cr2O3 nanosheets and enable their use in memristors with reconfigurable dual-mode memristive switching. The Cr2O3 nanosheets were inclined-grown on a SiO2/Si substrate with tailored thickness from 5.9 to 40 nm and tunable lateral size from 3 to 36 µm by a molecular sieve-assisted strategy. Benefiting from the inclined growth characteristics, the nanosheets can be transferred to arbitrary substrates by simple and quick mechanical pressing without any chemical etching contamination. The constructed Ag/Cr2O3/Au memristor shows reversible modulation between volatile threshold switching and nonvolatile bipolar operation through compliance-current control. The resulting memristor also demonstrates a low threshold voltage of ∼0.35 V with good cycle-to-cycle and cross-device reproducibility in the volatile regime, together with low set/reset voltages around 1.0 V/-0.55 V and a representative ON/OFF ratio exceeding 106 in the nonvolatile regime. This dual-mode functionality originates from an Ag-filament-dominated mechanism assisted by intrinsic defects in Cr2O3, where limited filament growth yields volatile relaxation behavior, while robust filament bridging stabilizes nonvolatile states. These results reveal the potential of Cr2O3 nanosheets as a promising platform for multifunctional memristive applications.