Tunable Nonvolatile Memory Behaviors of PCBM-MoS₂ 2D Nanocomposites through Surface Deposition Ratio Control

Efficient preparation of single-layer two-dimensional (2D) transition metal dichalcogenides, especially molybdenum disulfide (MoS₂), offers readily available 2D surface in nanoscale to template various materials to form nanocomposites with van der Waals heterostructures (vdWHs), opening up a new dimension for the design of functional electronic and optoelectronic materials and devices. Here, we report the tunable memory properties of the facilely prepared [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM)-MoS₂ nanocomposites in a conventional diode device structure, where the vdWHs dominate the electric characteristics of the devices for various memory behaviors depending on different surface deposition ratios of PCBM on MoS₂ nanosheets. Both nonvolatile WORM and flash memory devices have been realized using the new developed PCBM-MoS₂ 2D composites. Specially, the flash characteristic devices show rewritable resistive switching with low switching voltages (∼2 V), high current on/off ratios (∼3 × 10²), and superior electrical bistability (>10⁴ s). This research, through successfully allocating massive vdWHs on the MoS₂ surface for organic/inorganic 2D nanocomposites, illustrates the great potential of 2D vdWHs in rectifying the electronic properties for high-performance memory devices and paves a way for the design of promising 2D nanocomposites with electronically active vdWHs for advanced device applications.