Multistate Memory Enabled by Interface Engineering Based on Multilayer Tungsten Diselenide.

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• The demand for miniaturized memory devices with high data storage capacity is increasing.
• Atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDs) are suitable for flexible electronics and high-density integration.
• Multistate memory devices based on TMDs offer significant potential for data storage applications.

Purpose of the Study:

• To develop multistate data storage capabilities in transistors.
• To investigate the role of interface engineering in achieving multistate memory effects.
• To explore the potential of tungsten diselenide (WSe2) for high-performance memory devices.

Main Methods:

• Fabrication of multilayer WSe2 transistors on SiO2 substrates.
• Interface engineering by controlling trapped water and oxygen molecules.
• Utilizing laminated gold thin film electrodes for improved contact interfaces.
• Employing oxygen plasma treatment to manipulate interface trap states.

Main Results:

• Achieved multistate data storage in WSe2 transistors by controlling gate voltage pulses.
• Demonstrated a large switching ratio of up to 10^5 with high cycling endurance.
• Identified trapped H2O/O2 molecules at the SiO2/WSe2 interface as key to multistate behavior and hysteresis.
• Showcased the ability to manipulate memory performance via oxygen plasma treatment.

Conclusions:

• Interface engineering is a viable strategy for creating multistate memory devices.
• WSe2 transistors exhibit promising characteristics for high-density data storage.
• Control over interface trap states offers a pathway for tunable memory device performance.
• This work provides insights into trap state-associated applications in 2D materials.