Resistive-switching crossbar memory based on Ni-NiO core-shell nanowires

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Resistive-switching memory (RRAM) is a promising nonvolatile memory technology for device scaling.
• Achieving ultra-high memory densities (1 Tb cm⁻²) requires advanced fabrication methods beyond traditional lithography.
• Bottom-up synthesis and assembly of nanostructures are crucial for next-generation memory arrays.

Purpose of the Study:

• To demonstrate a RRAM memory device utilizing core-shell nickel-nickel oxide (Ni-NiO) nanowires (NWs).
• To investigate the feasibility of using NWs for high-density, low-cost crossbar memory architectures.
• To confirm the metal-insulator transition occurs within the NiO shell of the NWs.

Main Methods:

• Synthesis and assembly of core-shell Ni-NiO NWs.
• Fabrication of NW crossbar memory devices by overlapping NWs or connecting them to gold electrodes.
• Electrical characterization to measure resistance changes and confirm switching behavior.

Main Results:

• Demonstrated a resistance change of at least two orders of magnitude in the Ni-NiO NW RRAM device.
• Unequivocally showed that the metal-insulator switching occurs in the NiO shell layer.
• Fabrication is not limited by lithography, suggesting a pathway for scalable memory arrays.

Conclusions:

• Core-shell Ni-NiO NWs are effective active switching layers for RRAM devices.
• The NW-based crossbar architecture offers a promising route to ultra-high-density, low-cost nonvolatile memory.
• This bottom-up approach provides a foundation for memory with enhanced storage stability.