Multilevel MoS₂ Optical Memory with Photoresponsive Top Floating Gates

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Optoelectronic memory devices offer potential for advanced applications like image sensing and parallel data processing.
• Controlling device states with electrical and optical signals is crucial for next-generation electronics.

Purpose of the Study:

• To investigate MoS2-based optoelectronic memory devices with top floating gates.
• To explore the impact of different floating gate materials (Au, graphene, MoS2) on device performance.
• To analyze the observed multilevel optical memory effects.

Main Methods:

• Fabrication of MoS2-based devices with top floating gates (Au, graphene, MoS2).
• Characterization of device switching behavior using electrical and optical pulses (405 nm, 532 nm, 635 nm).
• Evaluation of on/off ratios, retention times, and optical memory effects under varying light conditions.

Main Results:

• Achieved stable and reliable switching with an on/off ratio of ~10^6 and retention time >10^4 s using 405 nm light and gate voltage pulses.
• Observed multilevel optical memory effects dependent on wavelength and dosage with 532 nm or 635 nm light.
• MoS2 floating gate devices showed higher light sensitivity, indicating photoexcited carriers in the floating gate are key to multilevel memory.

Conclusions:

• The developed MoS2-based optoelectronic memory devices demonstrate promising performance for optical data storage.
• Multilevel optical memory effects can be tuned by selecting appropriate top floating gate materials.
• The top floating gate structure presents a novel approach for designing advanced optoelectronic memory devices.