Patterned tungsten disulfide/graphene heterostructures for efficient multifunctional optoelectronic devices.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Scaling up high-performing graphene-based optoelectronic devices remains a significant challenge.
• Tungsten disulfide (WS2) and graphene heterostructures offer potential for novel optoelectronic applications.

Purpose of the Study:

• To report an original approach for fabricating efficient optoelectronic devices using scalable WS2/graphene heterostructures.
• To demonstrate the potential of these devices for photodetectors and 2D data storage.

Main Methods:

• Patterned growth of WS2 on graphene.
• Fabrication of photodetectors using WS2 on epitaxial graphene on silicon carbide (SiC).
• Characterization of device performance including responsivity, detectivity, and bandwidth.

Main Results:

• Photodetectors exhibited a maximum responsivity of ~220 A/W and detectivity of ~2.0 × 10^9 Jones under red light illumination.
• Achieved detectivity is 3 orders of magnitude higher than graphene-only devices.
• Observed persistent photocurrent with high charge retention at shorter wavelengths due to SiC substrate trap levels.

Conclusions:

• WS2/graphene optoelectronic devices can be fabricated in a scalable manner with promising performance.
• The combination of wavelength-selective memory, enhanced responsivity, and fast detection makes these devices suitable for 2D data storage.