Direct Charge Trapping Multilevel Memory with Graphdiyne/MoS₂ Van der Waals Heterostructure.

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Electronics

Background:

• Direct charge trapping memory, a novel dielectric-free concept, faces limitations due to insufficient localized electronic states for effective charge trapping.
• Advancing this technology requires materials with abundant hybrid states to enhance charge-trapping capabilities.

Purpose of the Study:

• To propose and demonstrate a van der Waals heterostructure utilizing 2D graphdiyne (GDY) with rich hybrid states for advanced direct charge trapping memory.
• To investigate the performance of a GDY/MoS2 based memory device for high-performance dielectric-free electronics.

Main Methods:

• Fabrication of ultrathin 2D GDY with a smooth surface using plasma etching for van der Waals coupling.
• Construction of a direct charge-trapping memory device using plasma-treated 2D GDY as the charge-trapping layer and MoS2.
• Characterization of the memory device's electrical and opto-electronic properties, including memory window and on/off ratio.

Main Results:

• Achieved a large memory window of 90 V and a high on/off ratio of approximately 8 × 10^7 in the GDY/MoS2 bilayer memory.
• Demonstrated two operating modes, enabling data storage capabilities of 9 and 10 current levels in electronic and opto-electronic modes, respectively.
• Successfully utilized 2D GDY as a charge-trapping center due to its rich hybrid states.

Conclusions:

• The GDY/MoS2 heterostructure offers a promising strategy for high-performance dielectric-free electronics, particularly in optical memories and artificial synaptic devices.
• Introduced a novel application of 2D graphdiyne as a charge-trapping material with abundant hybrid states.
• Paved the way for next-generation memory devices by overcoming limitations of traditional dielectric-based memory.